CN110635029A - A dual-band optically encrypted resistive variable memory and its preparation method, writing method and reading method - Google Patents

Abstract

The present invention provides a dual-band optically encrypted resistive memory, the resistive memory comprises: a glass substrate located at the lowest layer, an FTO lower electrode located on the glass substrate, and an AZO electrode located on the surface of the FTO lower electrode A seed layer, a ZnO nanorod array on the AZO seed layer, a PdS film layer on the ZnO nanorod array, an Al upper electrode on the PdS film layer; wherein, the PdS film layer A heterojunction structure is formed with the ZnO nanorod array, and the AZO seed layer is spin-coated with two layers and annealed. The dual-band optical encryption resistive memory of the present invention can work under single power supply and photoelectric dual control, and can realize different resistance states under different wavelengths of light, and the writing and reading of information require specific photoelectric conditions , can effectively avoid the appearance of misoperation, and at the same time achieve the purpose of information encryption.

Description

A dual-band optically encrypted resistive variable memory and its preparation method, writing method and reading take method

technical field

The invention belongs to the field of semiconductor devices, in particular to a dual-band optically encrypted resistive memory and a preparation method thereof.

Background technique

With the development and progress of science and technology, optoelectronic devices are developing towards multi-function, practicality and portability. Among them, the multifunctional development of data storage devices is a research hotspot. Using the photoresponse characteristics of semiconductor materials and the resistive characteristics of semiconductor materials, photoelectrically adjustable resistive devices can be designed to realize light detection, multi-state information storage, etc. Functionally integrated optoelectronic devices.

Resistive variable memory is a brand-new electronic device, which is based on the fact that the resistance of the material can be reversibly switched between a high-resistance state and a low-resistance state under the stimulation of an external voltage (electric field). Resistive variable memory has the advantages of high storage density, fast erasing and writing speed, multiple repetitions, and multi-value storage. Therefore, the application of resistive variable memory is becoming more and more extensive. Encrypt the resistive variable memory.

Contents of the invention

In view of this, the present invention aims to propose a dual-band optically encrypted resistive variable memory and its preparation method, writing method and reading method, which can work under single power supply and photoelectric dual control, and can operate under different wavelengths of light To achieve different resistance states, the writing and reading of information requires specific photoelectric conditions, which can effectively avoid the occurrence of misoperations and achieve the purpose of information encryption.

In order to achieve the above object, technical solution of the present invention is achieved in that way:

A dual-band optical encryption resistive memory, the resistive memory includes:

The bottom glass substrate,

an FTO lower electrode located on the glass substrate,

an AZO seed layer located on the surface of the FTO lower electrode,

an array of ZnO nanorods on said AZO seed layer,

a PdS film layer on the ZnO nanorod array,

An Al upper electrode located on the PdS thin film layer;

Wherein, the PdS film layer and the ZnO nanorod array form a heterojunction structure,

The AZO seed layer is spin-coated in two layers, and annealed.

Further, the thickness of the FTO lower electrode is 400nm, the thickness of the ZnO nanorod array is less than 3 μm, and the thickness of the Al upper electrode is 100nm-150nm.

Further, the Al upper electrode of the resistive variable memory is connected to the positive pole of the power supply, and the lower electrode of the FTO is connected to the negative pole of the power supply, and is triggered by 2V-5V in the dark state and under light, which can be triggered to realize multi-level storage.

At the moment of switching the light source, the current will increase and decrease rapidly, which can instantly trigger the conversion of photocurrent and dark current.

The present invention also provides a method for preparing the above-mentioned dual-band optically encrypted resistive memory, the method comprising the following steps:

1) Mix zinc acetate dihydrate, aluminum nitrate and ethylene glycol methyl ether solution, and stir magnetically at room temperature; after mixing evenly, place it in a water bath at 60°C for magnetic stirring, and add 0.75mL of ethanolamine dropwise as a stabilizer, and keep the temperature constant Stir evenly to obtain a clear and transparent solution; after cooling to room temperature, transfer it to the refrigerator, and obtain a clear and transparent AZO sol-gel solution after standing and aging for 12 hours;

2) Form the lower electrode of square resistance FTO on a transparent glass substrate, and wipe the lower electrode of FTO with detergent until it is wiped clean to remove the dust adsorbed on its surface; then use detergent, acetone, isopropanol, Ultrasonic cleaning of the FTO lower electrode with absolute ethanol to remove organic matter and impurity particles adsorbed on its surface, then dry in a vacuum oven, and then treat the surface of the FTO lower electrode with oxygen plasma to improve its work function ;

3) Spin-coat two layers of AZO seed layer on the treated FTO lower electrode with a homogenizer: after the first spin coating, place it in a muffle furnace for annealing at 400°C for 15 minutes, and then let it cool to room temperature; the second spin coating Then place it in a muffle furnace for annealing at 400°C for 30 minutes, take it out and let it cool to room temperature;

4) Weighing 3.9256g of HMT and 8.3280g of Zn(NO3)2·6H2O were dissolved in deionized water respectively, stirred until clarified, then mixed the two solutions respectively, and stirred to obtain a solution concentration of 0.2M; Step 3) The obtained annealed substrate is wound on a slide glass, and then the slide glass is put into the reactor liner, and 70ml growth liquid is added in the reactor liner, and then the reactor is closed; The reaction kettle was placed in a constant temperature drying oven at 100°C for 3 hours;

5) Under the protection of Ar gas, add PbO, oleic acid and octadecene (ODE) into the three-necked flask in sequence, mix and heat at 150°C and stir, after the PbO is fully dissolved, lower it to 80°C and keep it warm, marked as solution A ; In the same way, thioacetamide (TAA) and octadecene (ODE) are added successively in another three-necked flask, so that thioacetamide (TAA) is gradually dissolved and marked as solution B; then solution B Quickly inject into solution A, and heat the reaction at 80°C for 10 minutes under the protection of Ar gas; then put the reaction product into ice water, cool down to room temperature, and wash it with acetone and ethanol several times, and obtain solid PdS quantum dots after drying ;

6) Dissolve the solid PdS quantum dots obtained in step 5) into chloroform, centrifuge repeatedly to get the supernatant to prepare a saturated quantum dot solution with a concentration of about 30mg/ml; then use a homogenizer to spin coat the saturated quantum dot solution On the surface of the ZnO nanorod array (4) generated in the step 4), vacuum drying for 1 h to remove residual solvent;

7) Move the intermediate obtained in step 6) to a vacuum coating system, and vapor-deposit metal Al with a thickness of 150 nm to form an Al upper electrode (6).

The present invention also provides a method for writing the dual-band optically encrypted resistive memory as described above, the method comprising the following steps:

A. Obtain a write instruction of the resistive variable memory;

B. Applying a positive write voltage signal to the resistive variable memory according to the write instruction;

C. The resistive medium layer of the resistive memory obtains a first resistance value;

D. Perform a write operation on the RRAM according to the first resistance value.

The present invention also provides a method for reading the dual-band optically encrypted resistive memory as described above, the method comprising the following steps:

A. Obtain a read instruction of the resistive variable memory;

B. Applying a read voltage signal to the resistive variable memory according to the read instruction;

C. The resistive medium layer of the resistive memory obtains a first resistance value;

D. Perform a read operation on the RRAM according to the first resistance value.

The present invention also provides a method for writing the dual-band optically encrypted resistive memory as described above, the method comprising the following steps:

A. Obtain a write instruction of the resistive variable memory;

B. Applying a forward write voltage signal and an optical pulse signal to the resistive variable memory according to the write instruction;

C. The resistive medium layer of the resistive memory acquires a second resistance value;

D. Perform a write operation on the RRAM according to the second resistance value.

The present invention also provides a method for reading the dual-band optically encrypted resistive memory as described above, the method comprising the following steps:

A. Obtain a read instruction of the resistive variable memory;

B. Applying a read voltage signal and an optical pulse signal to the resistive variable memory according to the read instruction;

C. The resistive medium layer of the resistive memory acquires a second resistance value;

D. Perform a read operation on the RRAM according to the second resistance value.

Wherein, the light pulse signal is an ultraviolet light pulse signal or a near-infrared light pulse signal.

Compared with the prior art, the dual-band optically encrypted resistive memory of the present invention has the following advantages:

(1) The PdS quantum dots used in the dual-band optical encryption resistive variable memory of the present invention are important IV-VI semiconductor materials, which have narrow bandgap (0.41eV), large excitonic Bohr radius (18nm), Strong quantum confinement effect and multi-exciton effect; ZnO is an n-type wide bandgap (3.37eV) semiconductor with a small exciton Bohr radius (1.8nm), contains a large number of lattice defects and surface states, and has controllable The optical and electrical properties of ZnO are important materials in the field of optoelectronics. Resistive switching devices based on ZnO nanomaterials also have excellent repeatability, retention and transparency. PdS QDs/ZnO NRs heterojunction is a typical narrow bandgap quantum dot/wide bandgap semiconductor structure. Since the conduction band bottom and valence band top of narrow bandgap PbS are higher than that of wide bandgap ZnO, it can form Good energy level matching enables positive and effective charge separation on the heterojunction interface; the most important thing is that nano-ZnO and nano-PbS have strong light absorption and photoresponse characteristics in the ultraviolet and near-infrared regions respectively. Based on this A resistive memory with dual-wavelength optical encryption performance can be manufactured.

Moreover, the resistance switching phenomenon of this resistance switching device is based on the formation and disconnection of conductive filaments of oxygen vacancies. The AZO seed layer is Al-doped ZnO prepared by high temperature annealing. High temperature annealing can increase the oxygen content of the AZO seed layer. Vacancy concentration, the AZO seed layer provides oxygen vacancies in the entire device structure, and the increase of oxygen vacancies in the AZO seed layer is conducive to the formation of conductive filaments and increases the stability of the device.

(2) The dual-band optically encrypted resistive variable memory of the present invention can also trigger photocurrents of different sizes in different resistance states by light of ultraviolet and near-infrared wavelengths on the basis of electrically regulating the high and low resistance states; Different wavelengths of light and different optical powers of the same wavelength can trigger photocurrents of different sizes; using these photocurrents of different sizes can realize multi-level storage; when reading, it is necessary to apply the photoelectric conditions when writing to read. The data written under this optoelectronic condition cannot be read by the data written under other optoelectronic conditions, thereby realizing optical encryption. The size of the photocurrent of the ultraviolet and near-infrared light control device is convenient and efficient, and can be combined with routine testing to obtain a high-performance memory; at the same time, it has good stability, fatigue resistance, and can be used repeatedly.

(3) In the preparation method of the dual-band light-encrypted resistive variable memory of the present invention, the concentration of the zinc oxide precursor solution for preparing ZnO nano-arrays is large, resulting in better orientation of ZnO nano-rods and a denser structure, preventing the generation of leakage current; Moreover, such a device can increase the photocurrent, and has little effect on the dark current, thereby increasing the photosensitivity of the device. At the same time, the rectification ratio of the device is also greatly improved, and the photoresponse characteristics of the device become better.

Description of drawings

The drawings constituting a part of the present invention are used to provide a further understanding of the present invention, and the schematic embodiments and descriptions of the present invention are used to explain the present invention, and do not constitute an improper limitation of the present invention. In the attached picture:

FIG. 1 is a schematic structural diagram of a dual-band optically encrypted resistive memory according to an embodiment of the present invention;

Fig. 2 is the absorption spectrogram of the ZnO nanorod described in the embodiment of the present invention;

Fig. 3 is the absorption spectrogram of the PdS quantum dot described in the embodiment of the present invention;

Fig. 4 is a diagram of information writing in the dark state and 375nm ultraviolet light irradiation of the dual-band optically encrypted resistive memory according to the embodiment of the present invention;

Fig. 5 is an information reading diagram of the dual-band optically encrypted resistive memory in the dark state and 375nm ultraviolet light irradiation according to the embodiment of the present invention;

FIG. 6 is a resistance state diagram of the dual-band optically encrypted resistive memory according to the embodiment of the present invention when reading information in the dark state and under the irradiation of 375nm ultraviolet light.

Explanation of reference signs:

1-glass substrate; 2-FTO lower electrode; 3-AZO seed layer; 4-ZnO nanorod array; 5-PdS thin film layer; 6-Al upper electrode.

Detailed ways

It should be noted that, in the case of no conflict, the embodiments of the present invention and the features in the embodiments can be combined with each other.

The present invention will be described in detail below with reference to the accompanying drawings and examples.

FIG. 1 is a schematic structural diagram of a dual-band optically encrypted resistive memory according to an embodiment of the present invention.

As shown in Figure 1, a dual-band optical encryption resistive memory, the resistive memory includes:

The bottom glass substrate 1,

The FTO lower electrode 2 located on the glass substrate 1,

the AZO seed layer 3 on the surface of the FTO lower electrode 2,

a ZnO nanorod array 4 located on the AZO seed layer 3,

a PdS thin film layer 5 on the ZnO nanorod array 4,

An Al upper electrode 6 located on the PdS thin film layer 5;

Wherein, the PdS thin film layer 5 and the ZnO nanorod array 4 form a heterojunction structure,

The AZO seed layer 3 is spin-coated in two layers and annealed.

Specifically, the thickness of the FTO lower electrode 2 is 400 nm, the thickness of the ZnO nanorod array 4 is less than 3 μm, and the thickness of the Al upper electrode 6 is 100 nm-150 nm.

The Al upper electrode 6 of the RRAM is connected to the positive pole of the power supply, and the FTO bottom electrode 2 is connected to the negative pole of the power supply. It is triggered by 2V-5V in the dark state and under light, and can be triggered to realize multi-level storage.

A method for preparing a dual-band optically encrypted resistive memory as described above, the method comprises the following steps:

1) Mix 2.7438g of zinc acetate dihydrate, 0.0234g of aluminum nitrate and 25mL of ethylene glycol methyl ether solution, and stir magnetically for 5 minutes at room temperature; after mixing evenly, place it in a 60°C water bath for magnetic stirring, and add 0.75mL of Ethanolamine was used as a stabilizer, and stirred evenly at constant temperature for 3 hours to obtain a clear and transparent solution; after cooling to room temperature, it was transferred to a refrigerator, and after standing and aging for 12 hours, a clear and transparent AZO sol-gel solution was obtained;

2) Form a sheet resistance FTO lower electrode 2 with a thickness of 400nm on a transparent glass substrate 1, and wipe the FTO lower electrode 2 with detergent until it is wiped clean to remove the dust adsorbed on its surface; then use detergent respectively , acetone, isopropanol, and absolute ethanol to ultrasonically clean the FTO lower electrode 2 for 10 minutes each time to remove organic matter and impurity particles adsorbed on its surface, and then dry it in a vacuum drying oven for 30 minutes. , the drying temperature is 80°C, and then the surface of the FTO lower electrode 2 is treated with oxygen plasma to improve its work function;

3) Spin-coat two layers of AZO seed layer 3 on the treated FTO lower electrode 2 with a homogenizer: after the first spin-coating, place it in a muffle furnace for annealing at 400°C for 15 minutes, and then let it cool to room temperature; After spin coating, place it in a muffle furnace for annealing at 400°C for 30 minutes, take it out and let it cool to room temperature;

4) Weighing 3.9256g of HMT and 8.3280g of Zn(NO3)2·6H2O were dissolved in deionized water respectively, stirred until clarified, then mixed the two solutions respectively, and stirred to obtain a solution concentration of 0.2M; Step 3) The obtained annealed substrate is wound on a slide glass, and then the slide glass is put into the reactor liner, and 70ml growth liquid is added in the reactor liner, and then the reactor is closed; The reaction kettle was placed in a constant temperature drying oven at 100°C for 3 hours;

5) Under the protection of Ar gas, add 0.36g of PbO, 2ml of oleic acid and 14ml of octadecene into the three-neck flask in sequence, mix and heat at 150°C, and keep it at 80°C after the PbO is fully dissolved, and mark it as a solution A; In the same way, add 0.12g of thioacetamide and 16ml of octadecene to another three-necked flask in turn, so that thioacetamide gradually dissolves and marks it as solution B; then quickly inject solution B into solution A In the same way, under the protection of Ar gas, the reaction was heated at 80°C for 10 minutes; after that, the reaction product was put into ice water, lowered to room temperature, washed with acetone and ethanol for several times, and dried to obtain solid PdS quantum dots;

6) Dissolve the solid PdS quantum dots obtained in step 5) into chloroform, centrifuge repeatedly to get the supernatant to prepare a saturated quantum dot solution with a concentration of about 30 mg/ml; then use a homogenizer at 2000r/min for a duration of For 20s, spin-coat the saturated quantum dot solution on the surface of the ZnO nanorod array 4 generated in the step 4), and dry in vacuum for 1h to remove the residual solvent;

7) Move the intermediate obtained in step 6) to a vacuum coating system, and vapor-deposit metal Al with a thickness of 150 nm to form an Al upper electrode 6 .

The dual-band optical encryption resistive memory of the present invention is based on the photoresponse of nano-ZnO to ultraviolet and the photoresponse of nano-PdS to near-infrared. Under the irradiation of ultraviolet light and near-infrared light, the photocurrent of the resistive memory increases with the Light of different wavelengths and light of different optical powers of the same wavelength can trigger different resistance states, which manifest as photocurrents of different sizes, so as to realize the writing and reading of multi-level information, and realize the Encryption of information, namely:

Resistive memory can generate currents of different sizes, that is, different resistance states, to complete the writing process under electrical triggering, 365-385nm ultraviolet light-electricity co-triggering and 960-1000nm near-infrared photo-electricity co-triggering.

When reading, only add the reading voltage without adding light, only the data written by a single electricity can be read, and the data written under the photoelectric synergy cannot be read; add the reading voltage and 365-385nm ultraviolet light, It can only read the data written under the synergy of 365-385nm ultraviolet light and electricity, and cannot read the data written by a single electricity and the data written under the synergy of 960-1000nm near-infrared light and electricity; The process of writing data and reading data under the synergy of infrared light and electricity is also the same, so as to achieve the purpose of information encryption.

Fig. 2 is the absorption spectrogram of the ZnO nanorod described in the embodiment of the present invention, as shown in Fig. 2, the ZnO nanoarray (NRs) has strong absorption in the ultraviolet region, but weak absorption in the visible region.

FIG. 3 is an absorption spectrum diagram of the PdS quantum dots described in the embodiment of the present invention. As shown in FIG. 3 , the first exciton absorption peak of PdS quantum dots (QDs) is around 980nm.

According to the characteristics of the above-mentioned resistive memory, the writing and reading methods of the resistive memory are introduced as follows:

a. Electric trigger:

A writing method of a dual-band optically encrypted resistive variable memory, the method comprising the following steps:

A. Obtain a write instruction of the resistive variable memory;

B. Applying a positive write voltage signal to the resistive variable memory according to the write instruction;

C. The resistive medium layer of the resistive memory is changed from the first high resistance state to the first low resistance state, that is, the first resistance value is obtained;

D. Perform a write operation on the RRAM according to the first resistance value.

A method for reading a dual-band optically encrypted resistive variable memory, the method comprising the following steps:

A. Obtain a read instruction of the resistive variable memory;

B. Apply a read voltage signal (less than the write/erase voltage) to the RRAM according to the read instruction;

C. The resistive medium layer of the resistive memory obtains a first resistance value;

That is, apply a voltage and read the current value corresponding to the first high resistance state or the first low resistance state, corresponding to 0 (high resistance state/off state) and 1 (low resistance state/on state) in binary respectively. ) two states, when corresponding to 1, also corresponds to the first resistance value;

D. Perform a read operation on the RRAM according to the first resistance value.

b. Photoelectric synergistic triggering (taking ultraviolet light as an example):

A writing method of a dual-band optically encrypted resistive variable memory, the method comprising the following steps:

A. Obtain a write instruction of the resistive variable memory;

B. Applying a forward write voltage signal and an ultraviolet light pulse signal to the resistive variable memory according to the write instruction;

C. The resistive medium layer of the resistive memory is changed from a second high-resistance state to a second low-resistance state, that is, a second resistance value is obtained;

D. Perform a write operation on the RRAM according to the second resistance value.

A method for reading a dual-band optically encrypted resistive variable memory, the method comprising the following steps:

A. Obtain a read instruction of the resistive variable memory;

B. Apply a read voltage signal (less than the write/erase voltage) to the RRAM according to the read instruction;

C. The resistive medium layer of the resistive memory acquires a second resistance value;

That is, when applying a voltage scan to the optical state unit, it is necessary to additionally increase the corresponding optical pulse, such as ultraviolet light; the high and low resistance states when no ultraviolet light is added are represented as 00 (light off high resistance state/off state) and 10 (light off high resistance state/off state) Off low resistance state/on state) two states, and the light pulse is set to the light off state during the output voltage scanning; in addition to the high and low resistance state when no ultraviolet light is added, there is also a high and low resistance state after adding ultraviolet light, applying While reading the voltage, the light pulse is in the light-on state, and the current value corresponding to the low-resistance state or high-resistance state after adding light is read (corresponding to the high and low resistance state of the light state in Figure 5), which correspond to 01 in binary respectively (light-on high-resistance state/off state) and 11 (light-on low-resistance state/conduction state); when corresponding to 11, it also corresponds to the second resistance value;

D. Perform a read operation on the RRAM according to the second resistance value.

Fig. 4 is a diagram of information writing in the dual-band optically encrypted resistive memory in the dark state and 375nm ultraviolet light irradiation according to the embodiment of the present invention. Specifically, as shown in Fig. 4, under ultraviolet light, the present invention provides The PdS QDs/ZnO NRs heterojunction dual-band photo-encrypted resistive variable memory, in the dark state, the voltage scanning range is: 0→+3V→0→–3V→0, the Al upper electrode 6 is connected to the positive electrode of the power supply, and the FTO under Electrode 2 is connected to the negative pole of the voltage source. During the test, current limiting protection (I _CC =10mA) is used to prevent the device from being burned out by excessive current. It can be seen that the device is initially in a high resistance state, and in the positive voltage range, the device changes from a high resistance state to a low resistance state. In the negative voltage range, the device exhibits an obvious negative differential resistance phenomenon, and the current increases first and then decreases with the increase of the voltage, and gradually turns from a low resistance state to a high resistance state. Add 375nm ultraviolet light to irradiate the device, and in the positive voltage range, the initial state of the device is a high resistance state. At 0.84V, it jumps from a high-impedance state to a low-impedance state. In the negative voltage range, the device exhibits an obvious negative differential resistance phenomenon, gradually turning from a low-resistance state to a high-resistance state. After adding 375nm ultraviolet light, the device will appear in different high and low resistance states, and the switch has a significant improvement compared with the dark state.

Figure 5 is an information reading diagram of the dual-band optically encrypted resistive memory in the dark state and 375nm ultraviolet light irradiation according to the embodiment of the present invention. Specifically, as shown in Figure 5, the PdS QDs/ZnO provided by the present invention NRs heterojunction dual-band optically encrypted resistive variable memory, in the dark state, read with a voltage of -0.1V, and obtain a set of current values in high and low resistance states (the current value is a negative value, here take the absolute value of the current and then Take log processing), this is the data written by electrical triggering in the dark state; add 375nm ultraviolet light and -0.1V voltage, and read another set of current values in high and low resistance states, which is the synergy of adding ultraviolet light and electricity The data written under the trigger; the reading of these two groups of data requires their own specific photoelectric conditions, which realizes the optical encryption of data. The writing and reading of data are the same under the condition of near-infrared light of 900-1000nm.

FIG. 6 is a resistance state diagram of the dual-band optically encrypted resistive memory according to the embodiment of the present invention when reading information in the dark state and under the irradiation of 375nm ultraviolet light. As shown in Figure 6, the PdS QDs/ZnO NRs heterojunction dual-band optically encrypted resistive memory provided by the present invention is read with a voltage of -0.1V, and under the condition of dark state and 375nm ultraviolet light irradiation, The resistance values of different high and low configurations produced by the device (converted by reading the voltage and the measured current value), which represent the data written by the device before.

The dual-band optically encrypted resistive memory based on PdS QDs/ZnO NRs heterojunction described in the present invention, on the basis of electrically regulating the high and low resistance states, can also put into near-infrared light through 365-385nm ultraviolet light and 900-1000nm Light in two bands of light triggers photocurrents in different resistance states. Light of different wavelengths and different optical powers of the same wavelength can trigger different photocurrents. Using these different photocurrents can achieve multi-level storage; the above process is The process of writing, in contrast, can only use the same photoelectric conditions to realize the reading of information, so as to realize optical encryption. The writing and reading of information requires specific photoelectric conditions, which can effectively avoid the occurrence of misoperation. The device can be combined with routine tests, and has the advantages of fatigue resistance, diversified use occasions, and repeated cycle use.

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

Claims (8)

1. A dual-band optical encryption resistive memory, characterized in that: the resistive memory comprises: the bottommost glass substrate (1), The FTO lower electrode (2) on the glass substrate (1), an AZO seed layer (3) on the surface of the FTO lower electrode (2), a ZnO nanorod array (4) on the AZO seed layer (3), a PdS film layer (5) on the ZnO nanorod array (4), An Al upper electrode (6) on the PdS thin film layer (5); Wherein, the PdS thin film layer (5) and the ZnO nanorod array (4) form a heterojunction structure, The AZO seed crystal layer (3) is spin-coated in two layers and annealed. 2. The dual-band optical encryption resistive variable memory according to claim 1, characterized in that: the thickness of the FTO lower electrode (2) is 400nm, the thickness of the ZnO nanorod array (4) is less than 3 μm, the The thickness of the Al upper electrode (6) is 100nm-150nm. 3. The dual-band optical encryption resistive variable memory according to claim 1, characterized in that: the Al upper electrode (6) of the resistive variable memory is connected to the positive pole of the power supply, and the lower electrode (2) of the FTO is connected to the negative pole of the power supply, and in the dark state With 2V-5V trigger under the light and light, it can be triggered to realize multi-level storage. 4. A method for preparing the dual-band optically encrypted resistive memory according to any one of claims 1-3, characterized in that: the method comprises the steps of: 1) Mix zinc acetate dihydrate, aluminum nitrate and ethylene glycol methyl ether solution, and stir magnetically at room temperature; after mixing evenly, place it in a water bath at 60°C for magnetic stirring, and add 0.75mL of ethanolamine dropwise as a stabilizer, and keep the temperature constant Stir evenly to obtain a clear and transparent solution; after cooling to room temperature, transfer it to the refrigerator, and obtain a clear and transparent AZO sol-gel solution after standing and aging for 12 hours; 2) Form a square resistance FTO lower electrode (2) on a transparent glass substrate (1), and wipe the FTO lower electrode (2) with detergent until it is wiped clean to remove the dust adsorbed on its surface; Clean the FTO lower electrode (2) ultrasonically with detergent, acetone, isopropanol, and absolute ethanol to remove organic matter and impurity particles adsorbed on its surface, then dry it in a vacuum oven, and then use oxygen plasma Treating the surface of the FTO lower electrode (2) to improve its work function; 3) Spin-coat two layers of AZO seed layer (3) on the treated FTO lower electrode (2) with a homogenizer: after the first spin coating, place it in a muffle furnace for annealing at 400°C for 15 minutes, and then let it cool to room temperature ; After the second spin coating, place it in a muffle furnace for annealing at 400°C for 30 minutes, take it out and let it cool to room temperature; 4) Weighing 3.9256g of HMT and 8.3280g of Zn(NO3)2·6H2O were dissolved in deionized water respectively, stirred until clarified, then mixed the two solutions respectively, and stirred to obtain a solution concentration of 0.2M; Step 3) The obtained annealed substrate is wound on a slide glass, and then the slide glass is put into the reactor liner, and 70ml growth liquid is added in the reactor liner, and then the reactor is closed; The reaction kettle was placed in a constant temperature drying oven at 100°C for 3 hours; 5) Under the protection of Ar gas, add PbO, oleic acid and octadecene into the three-necked flask in turn, mix and heat at 150°C, heat and stir at 150°C, and after the PbO is fully dissolved, lower it to 80°C and keep it warm, and mark it as solution A; According to the method, thioacetamide and octadecene were added to another three-necked flask in turn, so that thioacetamide was gradually dissolved and marked as solution B; then solution B was quickly injected into solution A, and it was also protected under Ar gas Heat the reaction at 80°C for 10min; then put the reaction product into ice water, cool down to room temperature, wash with acetone and ethanol several times in turn, and obtain solid PdS quantum dots after drying; 6) Dissolve the solid PdS quantum dots obtained in step 5) into chloroform, centrifuge repeatedly to get the supernatant to prepare a saturated quantum dot solution with a concentration of about 30mg/ml; then use a homogenizer to spin coat the saturated quantum dot solution On the surface of the ZnO nanorod array (4) generated in the step 4), vacuum drying for 1 h to remove residual solvent; 7) Move the intermediate obtained in step 6) to a vacuum coating system, and vapor-deposit metal Al with a thickness of 150 nm to form an Al upper electrode (6). 5. A writing method of the dual-band optical encryption resistive variable memory as claimed in any one of claims 1-3, characterized in that: the method comprises the steps of: A. Obtain a write instruction of the resistive variable memory; B. Applying a positive write voltage signal to the resistive variable memory according to the write instruction; C. The resistive medium layer of the resistive memory obtains a first resistance value; D. Perform a write operation on the RRAM according to the first resistance value. 6. A method for reading a dual-band optically encrypted resistive variable memory as claimed in claim 5, characterized in that: the method comprises the steps of: A. Obtain a read instruction of the resistive variable memory; B. Applying a read voltage signal to the resistive variable memory according to the read instruction; C. The resistive medium layer of the resistive memory obtains a first resistance value; D. Perform a read operation on the RRAM according to the first resistance value. 7. A writing method of the dual-band optical encryption resistive variable memory as claimed in any one of claims 1-3, characterized in that: the method comprises the steps of: A. Obtain a write instruction of the resistive variable memory; B. Applying a forward write voltage signal and an optical pulse signal to the resistive variable memory according to the write instruction; C. The resistive medium layer of the resistive memory acquires a second resistance value; D. Perform a write operation on the RRAM according to the second resistance value. 8. A method for reading a dual-band optically encrypted resistive variable memory as claimed in claim 7, characterized in that: the method comprises the steps of: A. Obtain a read instruction of the resistive variable memory; B. Applying a read voltage signal and an optical pulse signal to the resistive variable memory according to the read instruction; C. The resistive medium layer of the resistive memory acquires a second resistance value; D. Perform a read operation on the RRAM according to the second resistance value.

Images