CN111162179B - A semi-transparent perovskite solar cell covered by a high reflection film and its preparation method - Google Patents

Abstract

The invention discloses a translucent perovskite solar cell covered with a high reflection film and a preparation method thereof. The solar cell comprises a substrate, an anode, a hole transport layer, a perovskite photoactive layer, an electronic The transmission layer, the cathode and the high-reflection film covering layer, the anode and the cathode are connected through an external power supply. This scheme introduces a high reflective layer behind the ultra-thin cathode of the translucent perovskite solar cell. The high reflective layer can reflect the light projected due to the thin cathode back to the inside of the device, so that the perovskite layer can absorb light twice, and then To increase the photogenerated current, at the same time, the high reflective layer acts as a package to isolate the erosion of the perovskite layer by water and oxygen in the air, prevent the metal electrodes from being oxidized, and improve the operational stability and storage stability of the device.

Description

A semi-transparent perovskite solar cell covered by a high reflection film and its preparation method

technical field

The invention relates to the field of photovoltaic devices, in particular to a translucent perovskite solar cell covered with a high reflection film and a preparation method thereof.

Background technique

Perovskite materials are due to their excellent optoelectronic properties, such as high absorption coefficient, adjustable band gap, high electron mobility and hole mobility, low exciton binding energy, long carrier diffusion length, low material cost and compatible The solution method has been widely used in the fields of light-emitting diodes, solar cells, lasers, detectors and other optoelectronic devices.

Semitransparent cells have attracted a lot of attention due to their use as glass in buildings. However, the thickness of metal electrodes in conventional translucent devices is thinner, which weakens the secondary absorption of the device (light absorption caused by the reflection of incident light by the metal electrodes), and finally leads to a significant decline in device performance, which cannot be compared with non-transparent devices. At the same time, water and oxygen in the air will cause the degradation of perovskite crystals, and the metal electrodes are easily oxidized in the air, resulting in poor storage and operation stability of the device.

Contents of the invention

The object of the present invention is to provide a semi-transparent perovskite solar cell covered with a high-reflection film and its preparation method. A high-reflection film constructed of multiple layers of high and low refractive index materials is introduced behind the ultra-thin cathode, which is mainly used to solve the problem of translucency. In the device, the light absorption is reduced due to the thin cathode, and the problem of device instability.

The technical scheme that the present invention adopts is as follows:

A translucent perovskite solar cell covered by a high reflection film, the solar cell comprising a substrate, an anode, a hole transport layer, a perovskite photoactive layer, an electron transport layer, a cathode and a high reflection film arranged in sequence The covering layer, the anode and the cathode are connected through an external power supply. Compared with traditional solar cells, this solution can reflect the cathode light to the perovskite active layer through the setting of the perovskite active layer and the high anti-mode covering layer, so that it can absorb light twice, thereby increasing the photogenerated current. Improve the performance of the device. At the same time, the high anti-mold covering layer can also isolate the inside of the battery from the outside world, avoiding the impact of water and oxygen in the air on the internal structure of the battery, and improving the stability of the device.

Preferably, the material of the perovskite photoactive layer is an organic-inorganic hybrid ABX ₃ type cubic crystal structure. Among them, A is an organic amine group (such as CH ₃ NH ₃ ⁺¹ (MA ⁺¹ ), CH(NH2) ₂ ⁺¹ , Cs ^+1, etc., a single or multiple combination); B is the fourth main group metal; X is A combination of monovalent halogen elements or multiple halogen elements.

Preferably, the thickness of the hole transport layer is 40-80nm, the thickness of the perovskite photoactive layer is 200-500nm, the thickness of the electron transport layer is 40-80nm, the thickness of the cathode is 5-20nm, and the thickness of the high reflection film covering layer is 100-200nm.

It is worth mentioning that in this solution, the anode uses a metal film or a metal oxide film. The metal oxide film can be an ITO film or a zinc oxide film or a tin oxide film. The metal film can be a metal such as gold, copper, or silver. film. In the present invention, the ITO thin film is preferably used as the anode, which has sufficient conductivity, large enough work function and good chemical stability, and can inject holes into the electrode of the hole transport layer.

The hole transport layer needs to use organic polymer materials with good hole transport characteristics and good chemical stability, such as 4,4'-cyclohexylene bis[N,N-di(p-tolyl)aniline] (TAPC), Poly[(9,9-Di-n-octylfluorenyl-2,7-diyl)-alt-(4,4'-(N-(4-n-butyl)phenyl)-diphenylamine)](TFB ), poly[bis(4-phenyl)(4-butylphenyl)amine](poly-TPD), poly[bis(4-phenyl)(2,4,6-trimethylphenyl)amine ](PTAA), polyethylenedioxythiophene-poly(styrene sulfonate) (PEDOT:PSS) and the like. The hole transport material of the present invention is preferably 4,4'-cyclohexylene bis[N,N-di(p-tolyl)aniline] (TAPC).

The electron transport layer adopts electron transport materials with good electron transport characteristics, low electron affinity film formation and good chemical stability, such as metal oxides (ZnO, TiO ₂ , SnO ₂ ), fullerenes C60, C70, Fullerene derivatives such as [6,6]-phenyl C61 butyric acid methyl ester (PC ₆₁ BM), any one of [6,6]-phenyl C ₇₁ butyric acid methyl ester (PC ₇₁ BM) or Various combinations, the electron transport material of the present invention is preferably [6,6]-phenyl C ₆₁ butyric acid methyl ester (PC ₆₁ BM).

The cathode adopts an electrode with strong enough conductivity, small enough work function, good chemical stability, and the ability to inject electrons into the electron transport layer, preferably a material with a low work function, usually using a metal oxide film (such as indium tin oxide ITO , zinc oxide, tin-zinc oxide) or metal film (alloy of metals such as lithium, magnesium, calcium, strontium, aluminum, indium or copper, gold, silver), the cathode material of the present invention is preferably Au.

The high-reflection film covering layer 7 is made of a material with strong light transmission and stable physical and chemical properties with a small extinction coefficient to carry out odd-numbered superposition of high and low refractive index films, and the high refractive index material is usually a metal oxide material such as MoO _3. MgO, WO ₃ , LiF, CsF are usually used as low refractive index materials.

In addition, the present invention also discloses a method for preparing a translucent perovskite solar cell covered by a high reflection film, comprising the following steps:

Step 1: Clean the substrate with detergent, acetone, deionized water and isopropanol solution in sequence.

Step 2: spin-coat the hole transport layer on the substrate after the drying treatment, and then anneal at 120 degrees Celsius for 20 minutes;

Step 3: Put the cooled substrate into the glove box, spin-coat the perovskite photoactive layer at a speed of 3000 rpm, and then anneal at 120 degrees Celsius for 10 minutes;

Step 4: Spin-coat the electron transport layer on the perovskite photoactive layer, and then anneal at 120 degrees Celsius for 20 minutes;

Step 5: Transfer the annealed substrate into a vacuum evaporation chamber to evaporate an ultra-thin metal cathode and a high-reflection film covering layer sequentially according to the diode device structure.

In summary, owing to adopting above-mentioned technical scheme, the beneficial effect of the present invention is:

1. In the present invention, a high-reflection layer is introduced behind the ultra-thin cathode of the translucent perovskite solar cell. The high-reflection layer can reflect the light projected due to the thin cathode back to the inside of the device, so that the perovskite layer undergoes two light absorption, thereby increasing the photogenerated current.

2. In the present invention, the introduced high-reflection film utilizes the difference in refractive index between adjacent film layers to enhance the reflection of incident light without impairing the light transmittance of the translucent device.

3. In the present invention, the high reflection film can play the role of encapsulation. Not only can it isolate the erosion of the perovskite layer by water and oxygen in the air, but more importantly, it can prevent the metal electrode from being oxidized, and improve the operation stability and storage stability of the device.

Description of drawings

In order to illustrate the technical solutions of the embodiments of the present invention more clearly, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the present invention, and thus It should be regarded as a limitation on the scope, and those skilled in the art can also obtain other related drawings based on these drawings without creative work.

Figure 1 is a schematic diagram of the structure of the semi-transparent perovskite solar energy in the present invention.

Fig. 2 is a comparison chart of light transmittance of Example 1 (control group) and Example 2 and Example 3 of the present invention.

Fig. 3 is a comparison chart of photoelectric conversion efficiency between Example 1 (control group) and Example 2 and Example 3 of the present invention.

Fig. 4 is a comparison chart of performance attenuation of Example 1 (control group) and Example 2 and Example 3 of the present invention.

Fig. 5 is a comparison chart of light transmittance of Example 4 (control group) and Example 5 and Example 6 of the present invention.

Fig. 6 is a comparison chart of photoelectric conversion efficiency between Example 4 (control group) and Example 5 and Example 6 of the present invention.

Fig. 7 is a comparison chart of performance attenuation of Example 4 (control group) and Example 5 and Example 6 of the present invention.

Marks in the figure: 1-substrate, 2-anode, 3-hole transport layer, 4-perovskite photoactive layer, 5-electron transport layer, 6-cathode, 7-high reflection film covering layer, 8-additional power supply.

Detailed ways

In order to make the object, technical solution and advantages of the present invention clearer, the present invention will be further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described here are only used to explain the present invention, and are not intended to limit the present invention, that is, the described embodiments are only some of the embodiments of the present invention, but not all of the embodiments. The components of the embodiments of the invention generally described and illustrated in the figures herein may be arranged and designed in a variety of different configurations.

Accordingly, the following detailed description of the embodiments of the invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely represents selected embodiments of the invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without making creative efforts belong to the protection scope of the present invention.

It should be noted that relative terms such as the terms "first" and "second" are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any relationship between these entities or operations. There is no such actual relationship or order between them. Furthermore, the term "comprises", "comprises" or any other variation thereof is intended to cover a non-exclusive inclusion such that a process, method, article, or apparatus comprising a set of elements includes not only those elements, but also includes elements not expressly listed. other elements of or also include elements inherent in such a process, method, article, or device. Without further limitations, an element defined by the phrase "comprising a ..." does not exclude the presence of additional identical elements in the process, method, article or apparatus comprising said element.

As shown in Figure 1, a translucent perovskite solar cell covered by a high-reflection film, the solar cell includes a substrate, an anode, a hole transport layer 3, a perovskite photoactive layer 4, and an electronic The transmission layer 5 , the cathode 6 and the high reflection film covering layer 7 , the anode and the cathode 6 are connected through an external power source 8 .

Specifically, as shown in FIG. 1 , the material of the perovskite photoactive layer 4 is an organic-inorganic hybrid ABX ₃ type cubic crystal structure.

Specifically, as shown in Figure 1, the thickness of the hole transport layer 3 is 40-80nm, the thickness of the perovskite photoactive layer 4 is 200-500nm, the thickness of the electron transport layer 5 is 40-80nm, and the thickness of the cathode 6 is 5 nm. -20nm, the thickness of the high reflection coating layer 7 is 100-200nm.

The present invention proposes a method for preparing a translucent perovskite solar cell covered by the above-mentioned high reflection film, comprising the following steps:

Step 1: Clean the ITO glass substrate 1 with detergent, deionized water, acetone, and isopropanol, and then dry it;

Step 2: Spin-coat the hole transport layer 3TAPC (8 mg/ml, dissolved in chlorobenzene) on the dried ITO glass substrate 1, and then perform annealing treatment;

Step 3: Put the cooled substrate into the glove box, and spin-coat the perovskite photoactive layer 4CH ₃ NH ₃ PbI ₃ (MAPbI ₃ , 1.2mol/ml, dissolved in dimethylformamide and di in a mixed solvent of methyl sulfoxide), and then annealed;

Step 4: Spin-coat the electron transport layer 5 (PC ₆₁ BM, 20mg/ml) on the perovskite photoactive layer 4, and then perform annealing treatment;

Step 5: Transfer the annealed substrate into the vacuum evaporation chamber to evaporate and deposit the ultra-thin metal cathode 6 and the high reflection film covering layer 7 sequentially according to the structure of the diode device.

Embodiment one: (as the control group of embodiment 2 and embodiment 3)

The diode device structure from bottom to top is as follows:

ITO/TAPC(40nm)/MAPbI ₃ (300nm)/PC ₆₁ BM(40nm)/Au(10nm)

The preparation method steps are as follows:

Step 1: Clean the flexible substrate ultrasonically using detergent, acetone, deionized water and isopropanol in sequence.

Step 2: spin-coat TAPC (8 mg/ml, dissolved in chlorobenzene) on the dried ITO glass substrate as a hole transport layer, and then anneal at 120 degrees Celsius for 20 minutes;

Step 3: Put the cooled substrate into the glove box and spin-coat the perovskite precursor at 3000 rpm for 40 seconds (1.2 mol of _MAPbI3 dissolved in 700 μL of dimethylformamide and 300 μL of dimethylformamide sulfoxide), and the perovskite was washed with 200 μl of chlorobenzene as anti-solvent during spin coating. Then annealing at 120 degrees Celsius for 10 minutes;

Step 4: Spin-coat the electron transport layer PC ₆₁ BM (dissolved in chlorobenzene at a concentration of 20 mg/ml) on the perovskite photoactive layer, and then anneal at 120 degrees Celsius for 20 minutes;

Step 5: Transfer the annealed substrate into a vacuum evaporation chamber and sequentially vapor-deposit 10 nm of Au as the cathode according to the diode device structure.

Device 1 (Device 1) was prepared in Example 1.

Embodiment two:

The diode device structure from bottom to top is as follows:

ITO/TAPC(40nm)/MAPbI ₃ (300nm)/PC ₆₁ BM(40nm)/Au(10nm)/[LiF(80nm)/MoO ₃ (40nm)/LiF(80nm)]

The preparation method steps are as follows:

Step 1: Clean the flexible substrate ultrasonically using detergent, acetone, deionized water and isopropanol in sequence.

Step 2: spin-coat TAPC (8 mg/ml, dissolved in chlorobenzene) on the dried ITO glass substrate as a hole transport layer, and then anneal at 120 degrees Celsius for 20 minutes;

Step 3: Put the cooled substrate into the glove box and spin-coat the perovskite precursor at 3000 rpm for 40 seconds (1.2 mol of _MAPbI3 dissolved in 700 μL of dimethylformamide and 300 μL of dimethylformamide sulfoxide), and the perovskite was washed with 200 μl of chlorobenzene as anti-solvent during spin coating. Then annealing at 120 degrees Celsius for 10 minutes;

Step 4: Spin-coat the electron transport layer PC ₆₁ BM (dissolved in chlorobenzene at a concentration of 20 mg/ml) on the perovskite photoactive layer, and then anneal at 120 degrees Celsius for 20 minutes;

Step 5: Transfer the annealed substrate into the vacuum evaporation chamber to vapor-deposit 10nm Au as the cathode and LiF(80nm)/MoO ₃ (40nm)/LiF(80nm) as the high-reflection film covering layer sequentially according to the diode device structure.

Device 2 (Device 2) was prepared in Example 2.

Example 3:

The diode device structure from bottom to top is as follows:

ITO/TAPC(40nm)/MAPbI ₃ (300nm)/PC ₆₁ BM(40nm)/Au(10nm)/[LiF(50nm)/MoO ₃ (25nm)/LiF(50nm)/MoO ₃ (25nm)/LiF( 50nm)]

The preparation method steps are as follows:

Step 1: Clean the flexible substrate ultrasonically using detergent, acetone, deionized water and isopropanol in sequence.

Step 2: spin-coat TAPC (8 mg/ml, dissolved in chlorobenzene) on the dried ITO glass substrate as a hole transport layer, and then anneal at 120 degrees Celsius for 20 minutes;

Step 3: Put the cooled substrate into the glove box and spin-coat the perovskite precursor at 3000 rpm for 40 seconds (1.2mol of MAPbI ₃ dissolved in 700L of dimethylformamide and 300L of dimethylformamide sulfoxide), and the perovskite was washed with 200 μl of chlorobenzene as anti-solvent during spin coating. Then annealing at 120 degrees Celsius for 10 minutes;

Step 4: Spin-coat the electron transport layer PC ₆₁ BM (dissolved in chlorobenzene at a concentration of 20 mg/ml) on the perovskite photoactive layer, and then anneal at 120 degrees Celsius for 20 minutes;

Step 5: Transfer the annealed substrate into the vacuum evaporation chamber to vapor-deposit 10nm Au as the cathode and LiF(50nm)/MoO ₃ (25nm)/LiF(50nm)/MoO ₃ (25nm)/ LiF (50nm) is used as a high reflection film covering layer.

Device 3 (Device 3) was prepared in Example 3.

Embodiment 4: (as the control group of embodiment 5 and embodiment 6)

The diode device structure from bottom to top is as follows:

ITO/TAPC(40nm)/Cs _0.1 FA _0.8 MA _0.1 PbI ₃ (300nm)/PC ₆₁ BM(40nm)/Au(10nm)

The preparation method steps are as follows:

Step 1: Clean the flexible substrate ultrasonically using detergent, acetone, deionized water and isopropanol in sequence.

Step 2: spin-coat TAPC (8 mg/ml, dissolved in chlorobenzene) on the dried ITO glass substrate as a hole transport layer, and then anneal at 120 degrees Celsius for 20 minutes;

Step 3: Put the cooled substrate into the glove box, and spin-coat the perovskite precursor at 3000 rpm for 40 seconds (1.58mol of Cs0.1FA0.8MA0.1PbI3 dissolved in 0.7ml of dimethyl formazan Amide and 0.3ml of dimethyl sulfoxide), and 200 microliters of chlorobenzene was used as an anti-solvent to wash the perovskite during spin coating. Then annealing at 120 degrees Celsius for 10 minutes;

Step 4: Spin-coat the electron transport layer PC ₆₁ BM (dissolved in chlorobenzene at a concentration of 20 mg/ml) on the perovskite photoactive layer, and then anneal at 120 degrees Celsius for 20 minutes;

Step 5: Transfer the annealed substrate into a vacuum evaporation chamber and sequentially vapor-deposit 10 nm of Au as the cathode according to the diode device structure.

Device 4 (Device 4) was prepared in Example 4.

Example 5:

The diode device structure from bottom to top is as follows:

ITO/TAPC(40nm)/Cs _0.1 FA _0.8 MA _0.1 PbI ₃ (300nm)/PC ₆₁ BM(40nm)/Au(10nm)/LiF(80nm)/WO ₃ (40nm)/LiF(80nm)

The preparation method steps are as follows:

Step 1: Clean the flexible substrate ultrasonically using detergent, acetone, deionized water and isopropanol in sequence.

Step 2: spin-coat TAPC (8 mg/ml, dissolved in chlorobenzene) on the dried ITO glass substrate as a hole transport layer, and then anneal at 120 degrees Celsius for 20 minutes;

Step 3: Put the cooled substrate into the glove box and spin-coat the perovskite precursor at 3000 rpm for 40 seconds (1.58mol of Cs _0.1 FA _0.8 MA _0.1 PbI ₃ dissolved in 0.7ml of dimethyl formamide and 0.3ml of dimethyl sulfoxide), and 200 microliters of chlorobenzene was used as an antisolvent to wash the perovskite during spin coating. Then annealing at 120 degrees Celsius for 10 minutes;

Step 4: Spin-coat the electron transport layer PC ₆₁ BM (dissolved in chlorobenzene at a concentration of 20 mg/ml) on the perovskite photoactive layer, and then anneal at 120 degrees Celsius for 20 minutes;

Step 5: Transfer the annealed substrate into the vacuum evaporation chamber and vapor-deposit 10nm Au as the cathode and LiF(80nm)/WO ₃ (40nm)/LiF(80nm) as the high-reflection film covering layer sequentially according to the diode device structure.

Device 5 (Device 5) was prepared in Example 5.

Embodiment 6:

The diode device structure from bottom to top is as follows:

ITO/TAPC(40nm)/Cs _0.1 FA _0.8 MA _0.1 PbI ₃ (300nm)/PC ₆₁ BM(40nm)/Au(10nm)/LiF(50nm)/WO ₃ (25nm)/LiF(50nm)/WO ₃ ( 25nm)/LiF(50nm)

The preparation method steps are as follows:

Step 1: Clean the flexible substrate ultrasonically using detergent, acetone, deionized water and isopropanol in sequence.

Step 2: spin-coat TAPC (8 mg/ml, dissolved in chlorobenzene) on the dried ITO glass substrate as a hole transport layer, and then anneal at 120 degrees Celsius for 20 minutes;

Step 3: Put the cooled substrate into the glove box, and spin-coat the perovskite precursor at 3000 rpm for 40 seconds (1.58mol of _MAPbI3 dissolved in 0.7ml of dimethylformamide and 0.3ml dimethyl sulfoxide), and the perovskite was washed with 200 μl of chlorobenzene as anti-solvent during spin coating. Then annealing at 120 degrees Celsius for 10 minutes;

Step 4: Spin-coat the electron transport layer PC ₆₁ BM (dissolved in chlorobenzene at a concentration of 20 mg/ml) on the perovskite photoactive layer, and then anneal at 120 degrees Celsius for 20 minutes;

Step 5: Transfer the annealed substrate into the vacuum evaporation chamber to vapor-deposit 10nm Au as the cathode and LiF(50nm)/WO ₃ (25nm)/LiF(50nm)/WO ₃ (25nm)/ LiF (50nm).

Device 6 (Device 6) was prepared in Example 6.

It can be seen from the above embodiments and corresponding drawings that, compared with traditional solar cells, the present invention can significantly improve its light transmittance and photoelectric conversion efficiency, and at the same time, can reduce performance attenuation and has strong practicability.

The above descriptions are only preferred embodiments of the present invention, and are not intended to limit the present invention. Any modifications, equivalent replacements and improvements made within the spirit and principles of the present invention should be included in the protection of the present invention. within range.

Claims (3)

1. A translucent perovskite solar cell covered by a high-reflection film, characterized in that, the solar cell comprises a substrate (1), an anode (2), a hole transport layer (3), a calcium Titanium ore photoactive layer (4), electron transport layer (5), cathode (6) and high reflection coating layer (7), wherein: The anode and the cathode (6) are connected by an external power supply (8); The high-reflection film covering layer (7) includes odd-numbered high-refractive-index materials and low-refractive-index materials; Wherein, the preparation method of the translucent perovskite solar cell covered by the high reflection film comprises the following steps: Step 1: cleaning the substrate (1) with detergent, acetone, deionized water and isopropanol solution in sequence; Step 2: Spin-coat the hole transport layer (3) on the substrate after the drying treatment, and then anneal at 120 degrees Celsius for 20 minutes; Step 3: Put the cooled substrate into the glove box, spin-coat the perovskite photoactive layer (4) at a speed of 3000 rpm, and then anneal at 120 degrees Celsius for 10 minutes; Step 4: Spin-coat the electron transport layer (5) on the perovskite photoactive layer, and then anneal at 120 degrees Celsius for 20 minutes; Step 5: Transfer the annealed substrate into a vacuum evaporation chamber to vapor-deposit an ultra-thin metal cathode (6) and a high-reflection film covering layer (7) sequentially according to the diode device structure. 2. the translucent perovskite solar cell covered by a kind of high reflection film according to claim 1, is characterized in that, the material of described perovskite photoactive layer (4) is organic, inorganic hybridization ABX ₃ type Cubic crystal structure. 3. the translucent perovskite solar cell covered by a kind of high reflection film according to claim 1, is characterized in that, described hole transport layer (3) thickness is 40-80nm, perovskite photoactive layer ( 4) The thickness is 200-500nm, the thickness of the electron transport layer (5) is 40-80nm, the thickness of the cathode (6) is 5-20nm, and the thickness of the high reflection film covering layer (7) is 100-200nm.

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