CN111554815A - Narrow-band multispectral perovskite photodetector, preparation method and use thereof - Google Patents

Abstract

The invention relates to a narrow-band multispectral perovskite photoelectric detector and a preparation method and application thereof, wherein the narrow-band multispectral perovskite photoelectric detector comprises a perovskite photoelectric detector and a diffraction waveguide grating positioned at one end of incident light of the perovskite photoelectric detector; the narrow-band multispectral perovskite photoelectric detector can regulate and control the absorption, scattering, diffraction and polarization characteristics of light with different wavelengths by regulating the depth, the period and the duty ratio of the structure of the diffraction waveguide grating, the refractive index of a grating layer material and the refractive index of a substrate, thereby realizing the function of regulating and filtering, carrying out narrow-band color filtering on incident light and realizing the response of narrow-band multispectral.

Description

Narrow-band multispectral perovskite photodetector, preparation method and use thereof

technical field

The invention belongs to the field of photodetectors, and relates to a narrow-band multispectral perovskite photodetector and a preparation method and application thereof.

Background technique

Photodetectors can detect and identify the detected object according to the light waves radiated or reflected by the detected object, and play an important supporting role in military, national defense, machine vision, biological sensing and imaging, optical communication and other application fields. Traditional photodetectors are mostly fabricated from materials such as silicon carbide, silicon, indium gallium arsenide, and germanium. However, the obtained devices have disadvantages such as high fabrication cost, complex process, limited detection wavelength range, or inflexibility.

In recent years, perovskite materials have been widely used in optoelectronic devices due to their high absorption coefficient, broad band coverage from ultraviolet to near-infrared, high carrier mobility, and micron-scale diffusion length. application. However, how to further design the device structure and give full play to the excellent optoelectronic properties of perovskite materials to meet the needs of various detections is the top priority of the research and development of multispectral detectors based on perovskite materials. The requirements of today's society for high-performance photodetectors include: narrow-band response to the detected spectrum, continuously adjustable peak wavelength of each response spectrum, high external quantum efficiency, fast response speed, and simultaneous integration of multiple band responses on one chip. , flexibility, simple preparation process, low cost, etc. However, by simply introducing perovskite materials into traditional device structures, the prepared narrow-band multispectral photodetectors currently have difficulties such as low external quantum efficiency, slow response speed, and insufficiently narrow bandwidth, which cannot exert the excellent performance of materials.

CN108258126A discloses an inorganic perovskite-based photodetector and a preparation method thereof. The preparation of the inorganic perovskite photodetector includes the following steps: Step S1, providing an ITO transparent conductive substrate, which is transparent to ITO Conductive substrate cleaning and pretreatment; step S2, preparing an anode modification layer on the ITO transparent conductive substrate, step S3, preparing a PbBr ₂ layer on the anode modification layer, step S4, preparing a CsPbBr ₃ inorganic perovskite photosensitive layer, step S5. Transfer the substrate with the _CsPbBr3 inorganic perovskite photosensitive layer to a vacuum coating machine, and grow a layer of C60 first cathode modification layer and a layer of Bphen second cathode modification layer by vacuum thermal deposition in turn, and finally A layer of Al is deposited on the cathode modification layer as a reflective electrode to complete the preparation of the detector device; CN209785975U discloses a perovskite photodetector, which includes a substrate, a bottom electrode, and a light absorption layer sequentially composed from bottom to top , a top electrode and an optical modulation layer, the optical modulation layer includes a lower dielectric layer and an upper light reflective film layer, the dielectric layer is selected from Si, ZnO, ZnS, Si ₃ N ₄ , Al ₂ O ₃ , SiO ₂ and one of TiO ₂ , the light-reflecting film layer is selected from one of Au, Ag, Al, Cu, Ni, Pt, Ti, TiN and ZrN; the photodetectors obtained by the above schemes all have a response speed , the problem of insufficient external quantum efficiency and insufficient bandwidth.

Therefore, on the basis of making minimal changes to the fabrication process and process conditions of perovskite photodetectors to retain the performance of the existing optimized perovskite photodetectors, a new method capable of achieving high efficiency and narrow bandwidth response was developed. Multispectral perovskite photodetectors and their fabrication methods are of great significance.

SUMMARY OF THE INVENTION

The object of the present invention is to provide a narrow-band multi-spectral perovskite photodetector, a preparation method and application thereof, and the narrow-band multi-spectral perovskite photodetector includes a perovskite photodetector and a perovskite photoelectric detector located in the perovskite photoelectric detector. Diffraction waveguide grating at one end of the incident light of the detector; the narrow-band multi-spectral perovskite photodetector of the present invention can adjust the depth, period, duty cycle of the structure of the diffraction waveguide grating, refractive index of the grating layer material, lining The bottom refractive index can be adjusted to adjust the absorption, scattering, diffraction and polarization characteristics of light of different wavelengths, and realize the adjustment filtering function. Integrate to achieve narrow-band multispectral responses.

In order to achieve this object of the invention, the present invention adopts the following technical solutions:

In a first aspect, the present invention provides a narrow-band multi-spectral perovskite photodetector, the narrow-band multi-spectral perovskite photodetector includes a perovskite photodetector and an incident beam located at the perovskite photodetector. Diffractive waveguide grating at one end of the light.

In the narrow-band multi-spectral perovskite photodetector of the present invention, a diffraction waveguide grating is arranged on one side of the incident light of the perovskite photodetector, and the adjustment and filtering function of the diffraction waveguide grating is realized by changing the structure and material of the diffraction waveguide grating. For narrow-band color filtering of incident light, multiple diffraction waveguide gratings are arranged at one end of the photodetector, so that simultaneous detection of multiple wavelengths can be realized and the accuracy of object identification is improved.

Traditional color filters can be divided into two types: absorption type and interference type according to their working methods: 1) The absorption type filter is based on the absorption principle of pigment to light. 2) The optical interference filter is based on the interference principle of light to filter light, and the thickness of each layer needs to be precisely adjusted. In order to obtain a narrow-band filter, up to 60 layers of film materials are usually required. The choice of thin-film materials is also limited, and the ultra-thin metal layer is easily oxidized, vulcanized or peeled off, and has a large incident angle dependence; therefore, the above-mentioned traditional color filters cannot achieve better narrow-band multispectral detection performance, and the present application The diffraction waveguide grating in the narrow-band multi-spectral perovskite photodetector is mainly composed of a subwavelength grating structure (the period is smaller than the incident wavelength) and a dielectric waveguide layer, and is an optical element that uses the diffraction waveguide effect to realize resonance filtering. The waveguide effect occurs in thin film structures with diffraction grating layers, and its most prominent feature is the efficient energy exchange between reflected and transmitted waves in the resonant wavelength range that is a few nanometers apart, resulting in nearly 100% transmission or reflection, which can be used To make high-efficiency reflection/transmission filters, it becomes an important component of optical systems such as laser high-reflection systems, polarization systems, optical imaging systems, biosensors, and wavelength division multiplexers. In the narrow-band multi-spectral perovskite photodetector described in this application, a transmission-type band-pass filter is designed and fabricated, and a high transmittance is obtained at the working wavelength by using the diffraction waveguide effect, thereby realizing narrow-band multi-spectral response.

The narrow band in the narrow-band multi-spectral perovskite photodetector of the present invention means that the bandwidth is less than 20 nm; the multi-spectral means that the photo-detector of the present invention can detect light of multiple wavelengths at the same time.

Preferably, the number of the diffractive waveguide gratings is ≥1, for example, 2, 3, 4, 5, or 6, etc., preferably ≥3.

Preferably, the diffractive waveguide grating comprises a sub-wavelength size grating.

Preferably, the diffraction waveguide grating is distributed in an array at one end of the incident light of the perovskite photodetector.

Preferably, the diffraction waveguide grating and the perovskite photodetector are connected by optical glue.

The diffractive waveguide grating of the present invention and the perovskite photodetector are connected in the above manner, which has little influence on the optical efficiency.

The combination of the diffraction waveguide grating of the present invention and the perovskite photodetector is more conducive to accurately identifying light of several wavelengths in the incident light that needs to be detected at the same time, thereby realizing a narrow-band multi-spectral response.

Preferably, the perovskite photodetector comprises a glass substrate, a transparent electrode, an electron transport layer, an N-type perovskite layer, a P-type perovskite layer, a hole transport layer, a metal electrode, and an encapsulating glass, which are arranged in sequence.

The perovskite photodetector described in the present invention is a homojunction perovskite photodetector, wherein the N-type perovskite layer and the P-type perovskite layer form a homojunction, and a built-in electric field is formed inside the photodetector, Strengthen the separation and transport of photogenerated carriers, thereby improving the response speed and external quantum efficiency (EQE) of the photodetector, solving the device response speed caused by the traditional photodetector only using an external electric field to separate photogenerated electron holes slow and low external quantum efficiency. The response speed of the homojunction perovskite photodetector of the present invention can reach 10 μs, and its EQE value can reach 10%. Compared with the traditional perovskite photodetector (EQE value is about 0.5%, response time is ms order of magnitude), the EQE value of the homojunction perovskite photodetector of the present invention is significantly improved, and the response time is significantly shortened.

In the homojunction perovskite in the homojunction perovskite photodetector of the present invention, there are many positively charged holes and negatively charged ionized impurities in the P-type perovskite layer, and under the action of the electric field , holes can move, while ionized impurities (ions) are fixed; while there are many mobile negative electrons and fixed positive ions in the N-type perovskite layer; the P-type perovskite layer and the N-type perovskite layer When the ore layers are in contact, holes diffuse from the P-type perovskite layer to the N-type perovskite layer near the interface, electrons diffuse from the N-type perovskite layer to the P-type perovskite layer, holes and electrons meet and recombine, and the carriers disappear. , therefore, there is a lack of carriers in the junction region near the interface, forming a space charge region, the space charge on one side of the P-type perovskite layer is negative ions, and the space charge on the side of the N-type perovskite layer is positive ions. A built-in electric field is generated near the interface, which strengthens the separation of electrons and holes, reduces the probability of carrier recombination, and improves the EQE value.

Preferably, the diffractive waveguide grating is located on the side of the glass substrate facing away from the transparent electrode.

Preferably, the electron transport layer includes a dense layer and a mesoporous layer adjacently arranged, and the mesoporous layer is adjacent to the N-type perovskite layer.

Here, the role of the mesoporous layer is to support and transport electrons, and the role of the dense layer is to transport electrons and block holes.

Preferably, the material of the dense layer is at least one of TiO ₂ , SnO ₂ or ZnO.

Preferably, the material of the mesoporous layer is TiO ₂ and/or Al ₂ O ₃ .

Preferably, the electron transport layer is prepared by solution method and/or atomic layer deposition technique.

Preferably, the thickness of the dense layer is 30-60 nm, such as 35 nm, 40 nm, 45 nm, 50 nm or 55 nm, and the like.

Preferably, the thickness of the mesoporous layer is 150-200 nm, such as 160 nm, 170 nm, 180 nm or 190 nm, and the like.

The molecular formula of the perovskite layer in the present invention is CH ₃ NH ₃ PbX ₃ , wherein X is any one or a combination of at least two of Cl, Br or I, and the combination exemplarily includes a combination of Cl and Br, I A combination of Cl or a combination of Br and I, etc. Wherein, in the preparation process of the N-type perovskite layer, the molar amount of the precursor PbX ₂ ≥ the molar amount of CH ₃ NH ₃ X, preferably, the molar ratio of PbX ₂ to CH ₃ NH ₃ X is (1-1.15 ):1. During the preparation of the P-type perovskite layer, the molar amount of the precursor PbX ₂ is less than the molar amount of CH ₃ NH ₃ X, and preferably, the molar ratio of PbX ₂ to CH ₃ NH ₃ X is 0.89-0.93.

Preferably, the thickness of the N-type perovskite layer is 400-500 nm, such as 410 nm, 420 nm, 430 nm, 440 nm, 450 nm, 460 nm, 470 nm, 480 nm or 490 nm, and the like.

Preferably, the thickness of the P-type perovskite layer is 50-100 nm, for example, 60 nm, 70 nm, 80 nm, or 90 nm.

Preferably, the ratio of the thickness of the N-type perovskite layer to the P-type perovskite layer is 4-10, such as 5, 6, 7, 8, or 9.

Preferably, the N-type perovskite layer is prepared by a solution method and/or an evaporation method.

Preferably, the hole transport layer includes at least one of spiro-OMeTAD, PTAA, CuSCN or CuPc.

Preferably, the thickness of the hole transport layer is 200-300 nm, such as 210 nm, 220 nm, 230 nm, 240 nm, 250 nm, 260 nm, 270 nm, 280 nm or 290 nm.

In the present invention, the size of the hole transport layer is controlled within the above-mentioned range, which is beneficial to the extraction of holes and their transfer to the electrode layer, thereby improving the response efficiency and EQE value of the device.

Preferably, the hole transport layer further includes lithium salt and/or cobalt salt.

Preferably, the transparent electrode is ITO or FTO transparent conductive glass.

Preferably, the sheet resistance of the transparent electrode is 10-25Ω, such as 12Ω, 14Ω, 16Ω, 18Ω, 20Ω, 22Ω or 24Ω, and the like.

Preferably, the transmittance of the transparent electrode is 80-95%, such as 82%, 84%, 86%, 88%, 90%, 92% or 94%.

Preferably, the metal electrode includes any one or a combination of at least two of Al, Ag or Au, and the combination exemplarily includes a combination of Al and Ag, a combination of Au and Al, or a combination of Ag and Au, etc. .

Preferably, the glass substrate and the encapsulating glass are each independently selected from glass with high light transmittance.

In a second aspect, the present invention provides a method for preparing a narrow-band multispectral perovskite photodetector as described in the first aspect, the method comprising first preparing the perovskite photodetector, and then preparing diffraction on the side of the incident light. waveguide grating;

Or prepare a diffraction waveguide grating first, and then prepare a perovskite photodetector on the side facing away from the incident light;

Or separately prepare a diffraction waveguide grating and a perovskite photodetector, and then combine the two to obtain the narrow-band multispectral perovskite photodetector.

Preferably, the diffractive waveguide grating is obtained by a nanoimprint method or an electron beam etching method.

Preferably, the nanoimprinting method includes: first performing nanoimprinting to achieve patterning, and then depositing grating materials to obtain the diffraction waveguide grating; or depositing grating materials first, nanoimprinting to achieve patterning, and then performing reactive ion etching etch to obtain the diffraction waveguide grating.

Preferably, the electron beam etching method comprises first using electron beam etching to realize patterning, and then depositing grating material to obtain the diffraction waveguide grating; or depositing grating material first, then performing electron beam etching patterning, reacting ions etching to obtain the diffraction waveguide grating.

Preferably, nano-imprinting is performed first to achieve patterning, and then the process of depositing the grating material specifically includes the following steps:

(I) depositing metal Cr on the substrate;

(II) spin-coating the corrosion resist, and then use a high-precision mask for nano-imprinting;

(III) removing the residual resist film on the surface of the product in the step (II) to obtain a patterned resist film, and depositing a material for preparing a diffraction waveguide grating;

(IV) peeling off the product in step (III), removing metal Cr and corrosion resist, to obtain the diffraction waveguide grating.

The thickness of the deposited metal Cr in the above step (I) is very thin.

Preferably, the substrate in step (I) is glass.

Preferably, the method for depositing metal Cr in step (I) is at least one of vacuum thermal evaporation method, magnetron sputtering method or atomic layer deposition method.

Preferably, in step (III), the method for removing the residual resist film on the surface of the product in step (II) includes reactive ion etching.

Preferably, the method for depositing the material in step (III) includes at least one of vacuum thermal evaporation method, magnetron sputtering method or atomic layer deposition method.

Preferably, the material deposited in step (III) includes at least one of Si, Al or Ag.

Preferably, the process of depositing the grating material first, realizing patterning by nano-imprinting, and then performing reactive ion etching specifically includes the following steps:

(I') sequentially depositing grating material and a layer of metal Cr on the substrate;

(II') spin-coating the resist, then use a high-precision mask for nano-imprinting, and then remove the residual film of the resist to obtain a patterned resist film;

(III') The product in (II') is subjected to reactive ion etching;

(IV') peeling off the product in step (III'), removing metal Cr and corrosion resist, to obtain the diffraction waveguide grating.

The thickness of the deposited metal Cr in the above step (I') is very thin.

Preferably, the substrate in step (I') is glass.

Preferably, the methods for depositing the grating material and metal Cr in step (I') are independently at least one selected from vacuum thermal evaporation, magnetron sputtering or atomic layer deposition.

Preferably, the process of first using electron beam etching to realize patterning, and then depositing grating material specifically includes the following steps:

(a) depositing metallic Cr on the substrate;

(b) spin-coating the resist, using electron beam exposure, and developing a patterned resist film;

(c) depositing a material for making a diffractive waveguide grating on the product of (b);

(d) peeling off the product in step (c), removing metal Cr and corrosion resist, to obtain the diffraction waveguide grating.

The thickness of the deposited metal Cr in the above step (a) is very thin.

Preferably, the substrate in step (a) is glass.

Preferably, the method for depositing metal Cr in step (a) is at least one of vacuum thermal evaporation method, magnetron sputtering method or atomic layer deposition method.

Preferably, the method for depositing the material in step (c) includes at least one of vacuum thermal evaporation method, magnetron sputtering method or atomic layer deposition method.

Preferably, the material deposited in step (c) includes at least one of Si, Al or Ag.

Preferably, the grating material is deposited first, followed by electron beam etching and patterning, and the process of reactive ion etching specifically includes the following steps:

(a') sequentially depositing grating material and a layer of metal Cr on the substrate;

(b') spin-coating the resist, using electron beam exposure, and developing a patterned resist film;

(c') Reactive ion etching of the product in (b');

(d') peeling off the product in step (c'), removing metal Cr and corrosion resist, to obtain the diffraction waveguide grating.

The thickness of the deposited metal Cr in the above step (a') is very thin.

Preferably, the substrate in step (a') is glass.

Preferably, the methods for depositing material and metal Cr in step (a') are independently selected from at least one of vacuum thermal evaporation method, magnetron sputtering method or atomic layer deposition method.

Preferably, the preparation method of the perovskite photodetector comprises the following steps:

(1) preparing an electron transport layer on the transparent electrode;

(2) preparing an N-type perovskite layer on the surface of the electron transport layer obtained in step (1);

(3) preparing a P-type perovskite layer on the surface of the N-type perovskite layer obtained in step (2);

(4) preparing a hole transport layer on the surface of the P-type perovskite layer obtained in step (3);

(5) preparing a metal electrode on the surface of the hole transport layer obtained in step (4) to obtain the perovskite photodetector.

Preferably, the method for preparing an electron transport layer on a transparent electrode in step (1) includes preparing a dense layer on the transparent electrode, and then preparing a mesoporous layer on the surface of the obtained dense layer to obtain the electron transport layer.

Preferably, the material of the dense layer is TiO ₂ , and the preparation process of the dense layer includes spin-coating a titanium source solution on the transparent electrode, and then annealing to obtain the dense layer.

Preferably, the titanium source is at least one of diisopropyl bis(acetylacetonyl)titanate, titanium tetrachloride or isopropyl titanate.

Preferably, the solvent of the titanium source solution is any one or a combination of at least two of 1-butanol, ethanol or isopropanol.

Preferably, the concentration of the titanium source solution is 0.1-0.2M, such as 0.12M, 0.14M, 0.15M, 0.16M or 0.18M, and the like.

Preferably, during the preparation of the dense layer, the spin coating speed is 1500-2500 rpm, such as 1600 rpm, 1700 rpm, 1800 rpm, 1900 rpm, 2000 rpm, 2100 rpm, 2200 rpm, 2300 rpm or 2400 rpm, etc.

Preferably, in the preparation process of the dense layer, the annealing temperature is 450-550°C, such as 460°C, 480°C, 500°C, 520°C or 540°C, and the annealing time is 20-40min, such as 22min, 25min, 27min, 30min, 32min, 35min or 38min etc.

Preferably, in the preparation process of the dense layer, the heating rate of annealing is 4-6°C/min, such as 4.2°C/min, 4.5°C/min, 4.8°C/min, 5°C/min, 5.2°C/min, 5.5℃/min or 5.8℃/min, etc.

Preferably, the material of the mesoporous layer is TiO ₂ , and the preparation method of the mesoporous layer includes spin-coating the TiO ₂ slurry on the surface of the dense layer, and then annealing to obtain the mesoporous layer.

Preferably, the TiO ₂ slurry is diluted with a solvent before spin coating.

Preferably, the solvent used for the dilution includes any one or a combination of at least two of ethanol, 1-butanol or isopropanol.

Preferably, in the preparation process of the mesoporous layer, the spin coating speed is 3500-4500 rpm, for example, 3600 rpm, 3800 rpm, 4000 rpm, 4200 rpm or 4400 rpm, and the like.

Preferably, the annealing temperature during the preparation of the mesoporous layer is 450-500°C, such as 455°C, 460°C, 465°C, 470°C, 475°C, 480°C, 485°C, 490°C or 495°C, etc., The annealing time is 20-40min, such as 25min, 30min or 35min, etc.

Preferably, in the preparation process of the mesoporous layer, the heating rate of the annealing is 4-6°C/min, for example, 4.5°C/min, 5°C/min, or 5.5°C/min.

Preferably, the method for preparing an N-type perovskite layer in step (2) includes spin-coating a mixed solution of CH ₃ NH ₃ X and PbX ₂ on the mesoporous layer, followed by heat treatment to obtain the N-type perovskite layer Ore layers, where the molar amount of PbX ₂ ≥ the molar amount of CH ₃ NH ₃ X.

Preferably, in the preparation process of the N-type perovskite layer, the molar ratio of PbX ₂ and CH ₃ NH ₃ X in the mixed solution of CH ₃ NH ₃ X and PbX ₂ is (1-1.15):1, for example 1:1.05 or 1:1.1 etc.

Preferably, in the preparation process of the N-type perovskite layer, the spin coating speed is 3500-4500 rpm, such as 3600 rpm, 3800 rpm, 4000 rpm, 4200 rpm or 4500 rpm, etc.

Preferably, in the preparation process of the N-type perovskite layer, anisole is added to the spin coating surface during the spin coating process.

Preferably, the solvent of the mixed solution of CH ₃ NH ₃ X and PbX ₂ is a mixed solution of dimethylformamide and dimethyl sulfoxide.

Preferably, the volume ratio of dimethylformamide and dimethyl sulfoxide in the mixed solution of dimethylformamide and dimethyl sulfoxide is (3-5): 1, such as 3.5: 1, 3.8: 1, 4:1 or 4.3:1, etc., preferably (3.5-4.5):1.

Preferably, in the preparation process of the N-type perovskite layer, the temperature of the heat treatment is 90-110°C, such as 95°C, 100°C or 105°C, and the time of the heat treatment is 8-12min, such as 9min, 10min or 11min and so on.

Preferably, the method for preparing a P-type perovskite layer in step (3) includes vacuum vapor deposition of PbX ₂ on the surface of the N-type perovskite layer obtained in step (2), and then immersing it in a CH ₃ NH ₃ X solution , to obtain the P-type perovskite layer, wherein the molar amount of PbX ₂ is less than the molar amount of CH ₃ NH ₃ X.

In the preparation process of the P-type perovskite layer of the present invention, a method of combining vacuum vapor deposition and impregnation is adopted, which can avoid the influence on the structure of the N-type perovskite layer during the preparation process of the P-type perovskite layer, thereby improving the preparation process. Effect.

Preferably, the molar ratio of PbX ₂ to CH ₃ NH ₃ X during the preparation of the P-type perovskite layer is 0.89-0.93, for example, 0.9, 0.91, or 0.92.

Preferably, the solvent of the CH ₃ NH ₃ X solution is isopropanol.

Preferably, in the preparation process of the P-type perovskite layer, annealing treatment is also included after the immersion, and the annealing temperature is 95-105°C, such as 96°C, 97°C, 98°C, 99°C, 100°C, 101°C, 102°C, 103°C or 104°C, etc., the annealing time is 5-20min, such as 8min, 10min, 12min, 15min or 18min, etc.

Preferably, the method for preparing the hole transport layer in step (4) includes spin-coating a solution containing spiro-OMeTAD on the surface of the P-type perovskite layer to obtain the hole transport layer.

Preferably, the solvent of the solution comprising spiro-OMeTAD comprises chlorobenzene.

Preferably, the solution containing spiro-OMeTAD further includes lithium salt and cobalt salt.

Preferably, the lithium salt includes Li-TFSI.

Preferably, the cobalt salt comprises tris[4-tert-butyl-2-(1H-pyrazol-1-yl)pyridine]cobalt(III)tris(1,1,1-trifluoro-N-[(tris Fluoromethyl)sulfonyl]methanesulfonamide salt) (FK209).

Preferably, the solution containing spiro-OMeTAD further contains 4-tert-butylpyridine.

Preferably, during the preparation of the hole transport layer, the rotation speed of the spin coating is 3250-3750 rpm, for example, 3300 rpm, 3350 rpm, 3400 rpm, 3450 rpm, 3500 rpm, 3550 rpm, 3600 rpm, 3650 rpm or 3700 rpm.

Preferably, in step (5), the metal electrode is prepared by a method of vacuum evaporation.

Preferably, the air pressure of the vacuum evaporation is less than 10 ^-4 Pa, for example, 5×10 ^-5 Pa, 10 ^-5 Pa or 5×10 ^-6 Pa and the like.

Preferably, the transparent electrode is located on a glass substrate.

Preferably, the perovskite photodetector is prepared first, and then the diffraction waveguide grating is prepared on the side of the incident light, or the diffraction waveguide grating is prepared first, and then the perovskite photodetector is prepared on the side facing away from the incident light. In the process, the perovskite photodetector and the diffractive waveguide grating share the same substrate.

Preferably, the diffractive waveguide grating and the perovskite photodetector are separately prepared, and then in the process of combining the two, the combining method is to use optical glue to bond.

As a preferred technical solution of the present invention, the preparation method of the narrow-band multispectral perovskite photodetector comprises the following steps:

The method includes first preparing a perovskite photodetector, and then preparing a diffractive waveguide grating on one side of the incident light, wherein the perovskite photodetector and the diffractive waveguide grating share the same substrate;

Or prepare the diffractive waveguide grating first, and then prepare the perovskite photodetector on the side facing away from the incident light, where the perovskite photodetector and the diffractive waveguide grating share the same substrate;

Or prepare the diffractive waveguide grating and the perovskite photodetector separately, and then bond the two with optical glue to obtain the narrow-band multispectral perovskite photodetector;

Wherein, the preparation method of the perovskite photodetector comprises the following steps:

(1) preparing an electron transport layer on a transparent electrode, which is located on a glass substrate;

(2) preparing an N-type perovskite layer on the surface of the electron transport layer obtained in step (1);

(3) preparing a P-type perovskite layer on the surface of the N-type perovskite layer obtained in step (2);

(4) preparing a hole transport layer on the surface of the P-type perovskite layer obtained in step (3);

(5) preparing a metal electrode on the surface of the hole transport layer obtained in step (4) to obtain the perovskite photodetector.

In a third aspect, the present invention provides the use of a narrowband multispectral perovskite photodetector as described in the first aspect for machine vision, biosensing and imaging or optical communication .

The narrow-band multispectral perovskite photodetector of the present invention has wavelength selectivity, so that it has important applications in many fields, such as photoelectric imaging and machine vision.

Compared with the prior art, the present invention has the following beneficial effects:

(1) The narrow-band multi-spectral perovskite photodetector of the present invention includes a perovskite photodetector and a diffraction waveguide grating at one end of its incident light. Narrow-band color filtering of light, so as to realize the narrow-band multi-spectral response of the photodetector, and the bandwidth of the narrow-band multi-spectral perovskite photodetector of the present invention can reach 10 nm;

(2) When multiple diffraction waveguide gratings are used in the narrow-band multi-spectral perovskite photodetector of the present invention, it can simultaneously detect multiple wavelengths, thereby helping to improve the recognition of objects.

Description of drawings

FIG. 1 is a schematic structural diagram of the narrow-band multispectral perovskite photodetector according to the present invention.

1-diffraction waveguide grating array, 10-first diffractive waveguide grating, 11-second diffractive waveguide grating, 12-third diffractive waveguide grating, 2-glass substrate, 3-transparent electrode, 4-electron transport layer, 40- Dense layer, 41- mesoporous layer, 5-N-type perovskite layer, 6-P-type perovskite layer, 7-hole transport layer, 8-metal electrode, 9-encapsulation glass.

Detailed ways

The technical solutions of the present invention are further described below through specific embodiments. It should be understood by those skilled in the art that the embodiments are only for helping the understanding of the present invention, and should not be regarded as a specific limitation of the present invention.

The schematic structural diagram of the narrow-band multi-spectral perovskite photodetector according to the present invention is shown in FIG. 1 . It can be seen from FIG. 1 that the narrow-band multi-spectral perovskite photodetector is a diffraction waveguide grating array 1 from bottom to top. , glass substrate 2, transparent electrode 3, electron transport layer 4, N-type perovskite layer 5, P-type perovskite layer 6, hole transport layer 7, metal electrode 8 and encapsulation glass 9, wherein the diffraction waveguide grating The array 1 is composed of a plurality of diffractive waveguide gratings (here, three diffractive waveguide gratings are taken as an example, namely the first diffractive waveguide grating 10, the second diffractive waveguide grating 11 and the third diffractive waveguide grating 12), and the electron transport layer 4 includes a dense layer 40 and a mesoporous layer 41, the mesoporous layer is adjacent to the N-type perovskite layer.

During the use of the narrow-band multispectral perovskite photodetector, the incident light is incident from one side of the diffraction waveguide grating array.

The following examples 1-5 all adopt the structure shown in the above-mentioned FIG. 1 , the perovskite layer in example 6 is an intrinsic perovskite layer, and other structures are exactly the same as those shown in the above-mentioned FIG. 1 .

Example 1

The structure of the narrow-band multispectral perovskite photodetector described in this example is as follows:

The structure of the perovskite photodetector: the transparent electrode is FTO transparent conductive glass with a sheet resistance of 10Ω and a transmittance of 95%; the electron transport layer includes a _TiO2 dense layer with a thickness of 30nm and a _TiO2 interlayer with a thickness of 200nm. Pore layer; N-type perovskite layer (the mole ratio of precursor PbX ₂ and CH ₃ NH ₃ X is 1.05:1) with a thickness of 480 nm, P-type perovskite layer (molar ratio of PbX ₂ and CH ₃ NH ₃ X) is 480 nm The thickness of the N-type perovskite layer and the P-type perovskite layer is 8, the metal electrode is an Au electrode, and the thickness of the gold electrode is 80 nm.

The diffraction waveguide grating array is a micro-nano grating array, which includes three micro-nano gratings arranged in parallel (referred to as the first micro-nano grating, the second micro-nano grating and the third micro-nano grating);

The preparation method of the narrow-band multispectral perovskite photodetector described in this embodiment:

In this embodiment, a diffractive waveguide grating is first prepared, and then a perovskite photodetector is prepared on the side facing away from the incident light, and the perovskite photodetector and the diffractive waveguide grating share the same substrate;

The preparation method of the diffraction waveguide grating comprises the following steps:

(1) depositing Si and a layer of metal Cr on the glass substrate in sequence;

(2) spin-coating the anti-corrosion adhesive, then use a high-precision mask for nano-imprinting, and then remove the residual film of the anti-corrosion adhesive to obtain a patterned anti-corrosion adhesive film;

(3) reactive ion etching is carried out to the product in step (2);

(4) stripping the product in step (3) of metal Cr and corrosion resist to obtain the diffraction waveguide grating;

Wherein, the preparation method of the perovskite photodetector comprises the following steps:

(1') Place the transparent electrode on the back of the substrate in step (1), spin-coat the 1-butanol solution of diisopropyl bis(acetylacetonate) titanate with a concentration of 0.15M on the transparent electrode, spin The coating rate was 2000rpm, and then annealed at 500°C for 30min to obtain the _TiO2 dense layer. The _TiO2 slurry (30NR-T, Dysol) was mixed and diluted with ethanol in a mass ratio of 6:1, and then it was diluted Spin-coating on the surface of the obtained TiO ₂ dense layer, annealing at 500° C. for 30 min, to obtain a TiO ₂ mesoporous layer, and obtaining the electron transport layer;

(2') Spin coating the mixed solution of CH ₃ NH ₃ X and PbX ₂ (the solvent is a mixed solution of dimethylformamide and dimethyl sulfoxide with a volume ratio of 4:1) in step (1') On the TiO ₂ mesoporous layer, the spin coating rate was 4000 rpm, and then the N-type perovskite layer was obtained by heat treatment at 100 °C for 10 min, wherein the molar ratio of PbX ₂ and CH ₃ NH ₃ X was 1.05:1;

(3') vacuum vapor deposition of PbX ₂ on the surface of the N-type perovskite layer obtained in step (2'), and then immersing it in a CH ₃ NH ₃ X solution to obtain the P-type perovskite layer, PbX ₂ and The molar ratio of CH ₃ NH ₃ X is 0.9;

(4') will contain spiro-OMeTAD, Li-TFSI, tris[4-tert-butyl-2-(1H-pyrazol-1-yl)pyridine]cobalt(III) tris(1,1,1-trifluoro) The chlorobenzene solution of -N-[(trifluoromethyl)sulfonyl]methanesulfonamide salt) and 4-tert-butylpyridine was spin-coated on the surface of the P-type perovskite layer at a spin-coating speed of 3500 rpm to obtain the empty space. A hole transport layer; wherein, in the chlorobenzene solution, spiro-OMeTAD, Li-TFSI and tris[4-tert-butyl-2-(1H-pyrazol-1-yl)pyridine]cobalt(III) tris(1, The mass ratio of 1,1-trifluoro-N-[(trifluoromethyl)sulfonyl]methanesulfonamide salt) is 7:1:0.25, and the mass ratio of spiro-OMeTAD to 4-tert-butylpyridine is 2.41mg/mL;

(5') Prepare an Au electrode on the surface of the hole transport layer obtained in step (4') by vacuum evaporation, and then cover the Au electrode with encapsulating glass to obtain the narrow-band multispectral perovskite photodetector.

Example 2

The difference between this embodiment and Embodiment 1 is that the transparent electrode in the perovskite photodetector is FTO transparent conductive glass, its sheet resistance is 25Ω, and the transmittance is 80%; the electron transport layer includes a thickness of 50nm. _TiO2 dense layer and _TiO2 mesoporous layer with a thickness of 200 nm; N-type perovskite layer (the molar ratio of precursor _PbX2 and _CH3NH3X is 1.15: ₁ ) with a thickness of 500 nm, P-type perovskite The thickness of the ore layer (the molar ratio of the precursor PbX ₂ to CH ₃ NH ₃ X is 0.92) is 80 nm, the thickness ratio of the N-type perovskite layer to the P-type perovskite layer is 6.25, and the metal electrode is an Ag electrode , the thickness of the Ag electrode is 100nm, and the preparation method of the perovskite photodetector includes the following steps:

(1') Place the transparent electrode on the back of the substrate in step (1), spin-coat the 1-butanol solution of diisopropyl bis(acetylacetonate) titanate with a concentration of 0.2 M on the transparent electrode, spin The coating rate was 2500rpm, and then annealed at 450°C for 40min to obtain the _TiO2 dense layer. The _TiO2 slurry (30NR-T, Dysol) was mixed and diluted with ethanol in a mass ratio of 5:1, and then it was diluted Spin-coating on the surface of the obtained TiO ₂ dense layer, annealing at 450° C. for 40 min, to obtain a TiO ₂ mesoporous layer, and obtaining the electron transport layer;

(2') Spin coating the mixed solution of CH ₃ NH ₃ X and PbX ₂ (the solvent is a mixed solution of dimethylformamide and dimethyl sulfoxide with a volume ratio of 4:1) in step (1') On the TiO ₂ mesoporous layer, the spin coating rate was 4000 rpm, and then the N-type perovskite layer was obtained by heat treatment at 100 °C for 10 min, wherein the molar ratio of PbX ₂ and CH ₃ NH ₃ X was 1.15:1;

(3') vacuum vapor deposition of PbX ₂ on the surface of the N-type perovskite layer obtained in step (2'), and then immersing it in a CH ₃ NH ₃ X solution to obtain the P-type perovskite layer, PbX ₂ and The molar ratio of CH ₃ NH ₃ X is 0.92;

(4') will contain spiro-OMeTAD, Li-TFSI, tris[4-tert-butyl-2-(1H-pyrazol-1-yl)pyridine]cobalt(III) tris(1,1,1-trifluoro) The chlorobenzene solution of -N-[(trifluoromethyl)sulfonyl]methanesulfonamide salt) and 4-tert-butylpyridine was spin-coated on the surface of the P-type perovskite layer at a spin-coating speed of 3500 rpm to obtain the empty space. A hole transport layer; wherein, in the chlorobenzene solution, spiro-OMeTAD, Li-TFSI and tris[4-tert-butyl-2-(1H-pyrazol-1-yl)pyridine]cobalt(III) tris(1, The mass ratio of 1,1-trifluoro-N-[(trifluoromethyl)sulfonyl]methanesulfonamide salt) is 6.5:1:0.3, and the mass ratio of spiro-OMeTAD to 4-tert-butylpyridine is 2.6mg/mL;

(5') Prepare an Ag electrode on the surface of the hole transport layer obtained in step (4') by vacuum evaporation, and then cover the package glass to obtain the narrow-band multispectral perovskite photodetector.

Other conditions are exactly the same as in Example 1.

Example 3

The difference between this embodiment and Embodiment 1 is that the thickness of the N-type perovskite layer is 480 nm, the thickness of the P-type perovskite layer is 80 nm, and the ratio of the thickness of the N-type perovskite layer to the P-type perovskite layer is 6 , and other conditions are exactly the same as in Example 1.

Example 4

The difference between this embodiment and Embodiment 1 is that the thickness of the N-type perovskite layer is 450 nm, the thickness of the P-type perovskite layer is 90 nm, and the ratio of the thickness of the N-type perovskite layer to the P-type perovskite layer is 5 , and other conditions are exactly the same as in Example 1.

Example 5

The difference between this example and Example 1 is that the perovskite layer only contains intrinsic perovskite (the molar ratio of PbX ₂ to CH ₃ NH ₃ X is 1:1), and its thickness is equal to the N-type calcium in Example 1 The sum of the thicknesses of the titanium layer and the P-type perovskite layer, and other conditions are exactly the same as those in Example 1.

Comparative Example 1

The difference between this comparative example and Example 5 is that the diffraction waveguide grating is not included, and other conditions are exactly the same as those of Example 5.

In Examples 1-5 of the present invention, the perovskite photodetector and the diffraction waveguide grating are combined to obtain a narrow-band multi-spectral perovskite photodetector, whose detection bandwidth range can reach below 20 nm, and can simultaneously detect multiple wavelengths of However, in Comparative Example 1, the diffraction waveguide grating is not included, and its detection bandwidth is over 200 nm, which cannot achieve the narrow-band multi-spectral detection effect of the present invention.

The applicant declares that the above are only specific embodiments of the present invention, but the protection scope of the present invention is not limited thereto. Those skilled in the art should Changes or substitutions that can be easily conceived within the technical scope all fall within the protection scope and disclosure scope of the present invention.

Claims (10)

1. The narrow-band multispectral perovskite photoelectric detector is characterized by comprising a perovskite photoelectric detector and a diffraction waveguide grating located at one end of incident light of the perovskite photoelectric detector.

2. The narrow-band multispectral perovskite photodetector of claim 1, wherein the number of the diffraction waveguide gratings is greater than or equal to 1;

preferably, the diffractive waveguide grating comprises a sub-wavelength sized grating;

preferably, the diffraction waveguide grating is distributed in an array at one end of the incident light of the perovskite photodetector.

3. The narrow-band multispectral perovskite photodetector of claim 1 or 2, wherein the perovskite photodetector comprises a glass substrate, a transparent electrode, an electron transport layer, an N-type perovskite layer, a P-type perovskite layer, a hole transport layer, a metal electrode, and encapsulation glass, which are arranged in sequence;

preferably, the diffraction waveguide grating is positioned on a side of the glass substrate opposite to the transparent electrode;

preferably, the electron transport layer comprises a dense layer and a mesoporous layer which are adjacently arranged, and the mesoporous layer is adjacent to the N-type perovskite layer;

preferably, the material of the compact layer is TiO₂、SnO₂Or ZnO;

preferably, the mesoporous layer is made of TiO₂And/or Al₂O₃；

Preferably, the electron transport layer is prepared by solution and/or atomic layer deposition techniques.

4. The narrow-band multispectral perovskite photodetector of claim 3, wherein the thickness of the N-type perovskite layer is 400-500 nm;

preferably, the thickness of the P-type perovskite layer is 50-100 nm;

preferably, the ratio of the thickness of the N-type perovskite layer to the thickness of the P-type perovskite layer is 4 to 10;

preferably, the N-type perovskite layer is prepared by a solution method and/or an evaporation method;

preferably, the hole transport layer comprises at least one of spiro-OMeTAD, PTAA, CuSCN or CuPc;

preferably, the hole transport layer further comprises a lithium salt and/or a cobalt salt;

preferably, the transparent electrode is ITO or FTO transparent conductive glass;

preferably, the square resistance of the transparent electrode is 10-25 Ω;

preferably, the transmittance of the transparent electrode is 80-95%;

preferably, the metal electrode includes any one or a combination of at least two of Al, Ag, or Au.

5. The method of fabricating a narrow band multi-spectral perovskite photodetector of any one of claims 1 to 4, wherein the method comprises fabricating the perovskite photodetector first, followed by fabricating a diffraction waveguide grating on the incident light side thereof;

or firstly preparing the diffraction waveguide grating, and then preparing the perovskite photoelectric detector on one side of the diffraction waveguide grating, which is back to incident light;

or respectively preparing the diffraction waveguide grating and the perovskite photoelectric detector, and then combining the two to obtain the narrow-band multispectral perovskite photoelectric detector.

6. The method of claim 5, wherein the diffractive waveguide grating is obtained by a nanoimprint method or an electron beam lithography method;

preferably, the nanoimprinting method includes: carrying out nanoimprint to realize patterning, and then depositing a grating material to obtain the diffraction waveguide grating; or depositing a grating material, performing nanoimprint to realize patterning, and performing reactive ion etching to obtain the diffraction waveguide grating;

preferably, the electron beam etching method comprises the steps of firstly realizing patterning by adopting electron beam etching, and then depositing a grating material to obtain the diffraction waveguide grating; or depositing a grating material, then carrying out electron beam etching patterning, and carrying out reactive ion etching to obtain the diffraction waveguide grating;

preferably, the process of performing nanoimprint to realize patterning and then depositing the grating material specifically includes the following steps:

depositing metal Cr on a substrate;

(II) spin-coating corrosion-resistant glue, and then performing nanoimprint by using a high-precision mask;

(III) removing the residual film of the etching resist on the surface of the product in the step (II) to obtain a patterned etching resist film, and depositing a material for preparing the diffraction waveguide grating;

(IV) stripping the product in the step (III) to remove metal Cr and the corrosion-resistant glue to obtain the diffraction waveguide grating;

preferably, the substrate of step (i) is glass;

preferably, the method for depositing the metal Cr in the step (I) is at least one of a vacuum thermal evaporation method, a magnetron sputtering method or an atomic layer deposition method;

preferably, the method for removing the residual film of the etching resist on the surface of the product in the step (II) in the step (III) comprises a reactive ion etching method;

preferably, the method for depositing the material in step (iii) comprises at least one of vacuum thermal evaporation, magnetron sputtering or atomic layer deposition;

preferably, the material deposited in step (iii) comprises at least one of Si, Al or Ag;

preferably, the process of depositing the grating material, performing nanoimprint to realize patterning, and then performing reactive ion etching specifically includes the following steps:

(I') sequentially depositing a grating material and a layer of metal Cr on a substrate;

(II') spin-coating corrosion inhibitor glue, then carrying out nano-imprinting by using a high-precision mask plate, and removing residual film of the corrosion inhibitor glue to obtain a graphical corrosion inhibitor glue film;

(III ') subjecting the product in (II') to reactive ion etching;

(IV ') stripping the product obtained in the step (III') to remove metal Cr and the corrosion-resistant glue to obtain the diffraction waveguide grating;

preferably, the substrate of step (I') is glass;

preferably, the method for depositing the grating material and the metal Cr in the step (I') is at least one selected from vacuum thermal evaporation, magnetron sputtering or atomic layer deposition;

preferably, the process of firstly realizing patterning by adopting electron beam etching and then depositing the grating material specifically comprises the following steps:

(a) depositing metal Cr on a substrate;

(b) spin-coating corrosion-resistant glue, exposing by using an electron beam, and developing to obtain a patterned corrosion-resistant glue film;

(c) depositing a material for preparing a diffraction waveguide grating on the product in (b);

(d) stripping the product in the step (c), and removing the metal Cr and the corrosion inhibiting glue to obtain the diffraction waveguide grating;

preferably, the substrate of step (a) is glass;

preferably, the method for depositing the metal Cr in the step (a) is at least one of a vacuum thermal evaporation method, a magnetron sputtering method or an atomic layer deposition method;

preferably, the method of depositing the material in step (c) comprises at least one of vacuum thermal evaporation, magnetron sputtering or atomic layer deposition;

preferably, the material deposited in step (c) comprises at least one of Si, Al or Ag;

preferably, the grating material is deposited first, and then the patterning by electron beam etching is performed, wherein the reactive ion etching process specifically includes the following steps:

(a') sequentially depositing a grating material and a layer of metal Cr on a substrate;

(b') spin-coating a corrosion inhibitor, exposing by using an electron beam, and developing to obtain a patterned corrosion inhibitor film;

(c ') subjecting the product of (b') to reactive ion etching;

(d ') stripping the product obtained in the step (c'), and removing the metal Cr and the corrosion-resistant glue to obtain the diffraction waveguide grating;

preferably, step (a') the substrate is glass;

preferably, the method for depositing the material and the metallic Cr in step (a') is at least one selected from vacuum thermal evaporation, magnetron sputtering and atomic layer deposition.

7. The method of claim 5 or 6, wherein the perovskite photodetector is fabricated by a method comprising the steps of:

(1) preparing an electron transport layer on the transparent electrode;

(2) preparing an N-type perovskite layer on the surface of the electron transport layer obtained in the step (1);

(3) preparing a P-type perovskite layer on the surface of the N-type perovskite layer obtained in the step (2);

(4) preparing a hole transport layer on the surface of the P-type perovskite layer obtained in the step (3);

(5) preparing a metal electrode on the surface of the hole transport layer obtained in the step (4) to obtain the perovskite photoelectric detector;

preferably, the method for preparing the electron transport layer on the transparent electrode in the step (1) includes preparing a dense layer on the transparent electrode, and then preparing a mesoporous layer on the surface of the obtained dense layer to obtain the electron transport layer;

preferably, the material of the compact layer is TiO₂The preparation process of the compact layer comprises spin-coating a titanium source solution on the transparent electrode, and then annealing to obtain the compact layer;

preferably, the titanium source is at least one of diisopropyl di (acetylacetonate) titanate, titanium tetrachloride or isopropyl titanate;

preferably, the solvent of the titanium source solution is any one or the combination of at least two of 1-butanol, ethanol or isopropanol;

preferably, the concentration of the titanium source solution is 0.1-0.2M;

preferably, in the preparation process of the compact layer, the speed of spin coating is 1500-;

preferably, in the preparation process of the dense layer, the annealing temperature is 450-550 ℃, and the annealing time is 20-40 min;

preferably, in the preparation process of the compact layer, the temperature rise rate of annealing is 4-6 ℃/min;

preferably, the mesoporous layer is made of TiO₂The preparation method of the mesoporous layer comprises the step of adding TiO₂The slurry is coated on the surface of the compact layer in a spinning mode, and then annealing is carried out, so that the mesoporous layer is obtained;

preferably, the TiO is₂Diluting the slurry by using a solvent before spin coating;

preferably, the solvent used for dilution comprises any one of ethanol, 1-butanol or isopropanol or a combination of at least two of the above;

preferably, in the preparation process of the mesoporous layer, the spin coating rate is 3500-4500 rpm;

preferably, the annealing temperature in the preparation process of the mesoporous layer is 450-;

preferably, in the preparation process of the mesoporous layer, the temperature rise rate of annealing is 4-6 ℃/min;

preferably, the method for preparing an N-type perovskite layer in the step (2) comprises adding CH₃NH₃X and PbX₂The mixed solution is spin-coated on the mesoporous layer and then is heated to obtain the N-type perovskite layer, wherein PbX₂Molar mass of not less than CH₃NH₃The molar amount of X;

preferably, in the preparation of said N-type perovskite layer, CH₃NH₃X and PbX₂In the mixed solution of (2) PbX₂And CH₃NH₃The molar weight ratio of X is (1-1.15) to 1;

preferably, in the preparation process of the N-type perovskite layer, the spin coating speed is 3500-4500 rpm;

preferably, in the preparation process of the N-type perovskite layer, anisole is added on the surface of the spin coating in the spin coating process;

preferably, the CH₃NH₃X and PbX₂The solvent of the mixed solution is mixed solution of dimethyl formamide and dimethyl sulfoxide;

preferably, the volume ratio of the dimethyl formamide to the dimethyl sulfoxide in the mixed solution of the dimethyl formamide and the dimethyl sulfoxide is (3-5) to 1, preferably (3.5-4.5) to 1;

preferably, in the preparation process of the N-type perovskite layer, the heating treatment temperature is 90-110 ℃, and the heating treatment time is 8-12 min;

preferably, the method for preparing the P-type perovskite layer in the step (3) comprises the step of carrying out vacuum vapor deposition PbX on the surface of the N-type perovskite layer obtained in the step (2)₂Then dipping it in CH₃NH₃In the solution of X, obtaining the P-type perovskite layer, wherein PbX₂Is less than CH₃NH₃The molar amount of X;

preferably, PbX is generated during the preparation of the P-type perovskite layer₂And CH₃NH₃The molar weight ratio of X is 0.89-0.93;

preferably, the CH₃NH₃The solvent of the X solution is isopropanol;

preferably, the method for preparing the hole transport layer in the step (4) includes spin-coating a solution containing spiro-OMeTAD on the surface of the P-type perovskite layer to obtain the hole transport layer;

preferably, the solvent of the spiro-OMeTAD containing solution comprises chlorobenzene;

preferably, the solution containing spiro-OMeTAD also comprises lithium salt and cobalt salt;

preferably, the lithium salt comprises Li-TFSI;

preferably, the cobalt salt comprises tris [ 4-tert-butyl-2- (1H-pyrazol-1-yl) pyridine ] cobalt (III) tris (1,1, 1-trifluoro-N- [ (trifluoromethyl) sulfonyl ] methanesulfonamide salt);

preferably, the solution comprising spiro-OMeTAD further comprises 4-tert-butylpyridine;

preferably, in the preparation process of the hole transport layer, the rotation speed of spin coating is 3250 and 3750 rpm;

preferably, the metal electrode in the step (5) is prepared by a vacuum evaporation method;

preferably, the pressure of the vacuum evaporation is less than 10^-4Pa；

Preferably, the transparent electrode is located on a glass substrate.

8. The method according to any one of claims 5 to 7, wherein the perovskite photodetector is fabricated first, followed by the fabrication of the diffraction waveguide grating on the side of the incident light, or the diffraction waveguide grating is fabricated first, followed by the fabrication of the perovskite photodetector on the side of the perovskite photodetector opposite to the incident light, wherein the perovskite photodetector and the diffraction waveguide grating share the same substrate;

preferably, in the process of preparing the diffraction waveguide grating and the perovskite photodetector respectively and then combining the two, the combination method is bonding by using optical glue.

9. The method according to any one of claims 5 to 8, characterized in that it comprises the steps of:

the method comprises the steps of firstly preparing a perovskite photoelectric detector, then preparing a diffraction waveguide grating on one side of incident light of the perovskite photoelectric detector, wherein the perovskite photoelectric detector and the diffraction waveguide grating share the same substrate;

or preparing the diffraction waveguide grating firstly, and then preparing a perovskite photoelectric detector on one side of the diffraction waveguide grating, which is back to incident light, wherein the perovskite photoelectric detector and the diffraction waveguide grating share the same substrate;

or respectively preparing the diffraction waveguide grating and the perovskite photoelectric detector, and then bonding the two through optical glue to obtain the narrow-band multispectral perovskite photoelectric detector;

the preparation method of the perovskite photoelectric detector comprises the following steps:

(1) preparing an electron transport layer on a transparent electrode, wherein the transparent electrode is positioned on a glass substrate;

(2) preparing an N-type perovskite layer on the surface of the electron transport layer obtained in the step (1);

(3) preparing a P-type perovskite layer on the surface of the N-type perovskite layer obtained in the step (2);

(4) preparing a hole transport layer on the surface of the P-type perovskite layer obtained in the step (3);

(5) and (5) preparing a metal electrode on the surface of the hole transport layer obtained in the step (4) to obtain the perovskite photoelectric detector.

10. Use of the narrow band multi-spectral perovskite photodetector of any one of claims 1 to 4, wherein the narrow band multi-spectral perovskite photodetector is used for machine vision, biosensing and imaging or optical communication.

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