Lead-based perovskite composite photosynaptic transistor and preparation method thereof

Abstract

The invention discloses a lead-based perovskite composite photosynapse transistor and a preparation method thereof.The lead-based perovskite composite photosynapse transistor is of a hierarchical structure and sequentially comprises a silicon dioxide / silicon substrate layer, a lead-based perovskite light absorption layer, an aluminum oxide tunneling layer, a zinc oxide semiconductor layer and a source / drain electrode layer from bottom to top, the source / drain electrode layer comprises a source electrode and a drain electrode which are respectively arranged on two sides of the upper surface of the zinc oxide semiconductor layer; the main component of the lead-based perovskite light absorption layer is CsPbBr3, and the aluminum oxide tunneling layer is used for improving the adhesiveness of the zinc oxide semiconductor layer, so that the zinc oxide semiconductor layer is uniform and compact; wherein the lead-based perovskite light absorption layer, the aluminum oxide tunneling layer and the zinc oxide semiconductor layer form a composite film layer, and a high potential barrier of the aluminum oxide tunneling layer limits the transfer speed and the recombination rate of a photon-generated carrier, so that the illumination recombination speed of the lead-based perovskite composite photosynaptic transistor is reduced. According to the invention, the linearity of the photosynapse transistor can be effectively improved.

Description

Technical Field

[0001] The present invention relates to the technical field of artificial vision, and particularly to a lead-based perovskite composite opto-synaptic transistor and a preparation method thereof. Background Art

[0002] Developing neuromorphic devices that mimic the information processing mode of the human brain helps to break through the bottleneck of existing artificial vision systems. In the biological nervous system, synapses are the basic units of functional connection, information processing, and learning between neurons. Therefore, developing artificial synaptic devices is an important step towards realizing a neuromorphic vision system. Among them, opto-synaptic transistors can directly sense optical signals and convert them into electrical signals by means of light-absorbing materials, thus realizing an efficient new artificial vision system integrating sensors, processors, and memories. Therefore, they are very suitable for high-speed computing systems and can perform calculations and pattern recognition at remarkable speeds and accuracies.

[0003] To improve the performance and accuracy of digital recognition and image processing, linearity is crucial as an indicator for evaluating the accuracy and stability of the system. High linearity of the system can achieve precise classification and processing of input signals, significantly enhancing the accuracy of recognition and processing. In tasks such as handwritten digit recognition and image preprocessing, small changes in input signals may lead to large fluctuations in results. Low linearity may result in misclassification and unstable results. Therefore, enhancing the linearity of the system is very important for improving accuracy, stability, and robustness. Currently, most optoelectronic synaptic devices mainly utilize the positive photoconductivity response characteristics of optical materials. However, due to the limitation of saturated photocurrent and some other factors (such as non-uniform semiconductor layers), opto-synaptic devices are prone to generating non-linear current signal responses. Summary of the Invention

[0004] In view of the above-mentioned partial defects of the prior art, the technical problem to be solved by the present invention is to provide a lead-based perovskite composite opto-synaptic transistor and a preparation method thereof, aiming to improve the linearity of the opto-synaptic transistor.

[0005] To achieve the above object, in the first aspect of the present invention, it is disclosed that the lead-based perovskite composite photonic synaptic transistor has a hierarchical structure, which successively includes from bottom to top: a silicon dioxide / silicon-based bottom layer, a lead-based perovskite light absorption layer, an aluminum oxide tunneling layer, a zinc oxide semiconductor layer, and a source / drain electrode layer. The source / drain electrode layer includes a source electrode and a drain electrode respectively disposed on both sides of the upper surface of the zinc oxide semiconductor layer. The main component of the lead-based perovskite light absorption layer is CsPbBr3. The aluminum oxide tunneling layer is used to improve the adhesion of the zinc oxide semiconductor layer, so that the zinc oxide semiconductor layer is uniform and dense. Among them, the lead-based perovskite light absorption layer, the aluminum oxide tunneling layer, and the zinc oxide semiconductor layer form a composite film layer. The high potential barrier of the aluminum oxide tunneling layer restricts the transfer speed and recombination rate of photo-generated carriers, so that the speed of the lead-based perovskite composite photonic synaptic transistor reaching photocurrent saturation is reduced.

[0006] In the second aspect of the present invention, a method for preparing a lead-based perovskite composite photonic synaptic transistor is disclosed, which is applied to the above-mentioned lead-based perovskite composite photonic synaptic transistor. The method includes:

[0007] Step S1: Dissolve lead bromide and cesium bromide in dimethyl sulfoxide according to a preset ratio to obtain a lead-based perovskite precursor solution;

[0008] Step S2: Spin-coat the lead-based perovskite precursor solution on a silicon dioxide / silicon substrate to form a lead-based perovskite film; perform vacuum pumping on the lead-based perovskite film to remove excess solvent, and obtain a lead-based perovskite film light absorption layer;

[0009] Step S3: Deposit aluminum oxide on the lead-based perovskite film light absorption layer to form the aluminum oxide tunneling layer; among them, the adhesion of the aluminum oxide to the lead-based perovskite film light absorption layer is greater than the adhesion of the zinc oxide to the lead-based perovskite film light absorption layer. The high potential barrier of the aluminum oxide tunneling layer restricts the transfer and recombination rate of photo-generated carriers, and reduces the speed of the lead-based perovskite composite photonic synaptic transistor reaching photocurrent saturation;

[0010] Step S4: Deposit zinc oxide on the aluminum oxide tunneling layer to form the zinc oxide semiconductor layer; among them, the adhesion of the zinc oxide to the aluminum oxide tunneling layer is greater than the adhesion of the zinc oxide to the lead-based perovskite film light absorption layer;

[0011] Step S5: Prepare a source electrode and a drain electrode on both sides of the upper surface of the zinc oxide semiconductor layer to form a source / drain electrode layer.

[0012] Optionally, the step S1 includes:

[0013] Dissolve lead bromide and cesium bromide in a molar ratio of 1:1 in dimethyl sulfoxide, and heat and stir at 70 °C for 2 hours to obtain the lead-based perovskite precursor solution; wherein, the concentration of the lead-based perovskite precursor solution is 0.08 M.

[0014] Optionally, before the step S2, the method further includes:

[0015] Filter the lead-based perovskite precursor solution using a filter head with a pore size of 0.22 μm.

[0016] Optionally, before the step S2, the method further includes:

[0017] Clean the silicon dioxide / silicon substrate with acetone, isopropyl alcohol, and deionized water respectively; perform oxygen plasma treatment on the silicon dioxide / silicon substrate to improve the surface hydrophilicity of the silicon dioxide / silicon substrate; wherein, the silicon dioxide / silicon substrate is n-type.

[0018] Optionally, the step S2 includes:

[0019] Place the silicon dioxide / silicon substrate in a nitrogen atmosphere, and set the spin coating speed to 3000 - 6000 rpm; drop the lead-based perovskite precursor solution preheated at 100 °C on the silicon dioxide / silicon substrate and spin coat to form a film;

[0020] Transfer the spin-coated silicon dioxide / silicon substrate to a vacuum chamber for vacuum pumping for a first preset duration to remove excess solvent and obtain the lead-based perovskite film light absorption layer.

[0021] Optionally, the step S3 includes:

[0022] Transfer the silicon dioxide / silicon substrate and the lead-based perovskite film light absorption layer to an atomic layer deposition chamber, and control the growth temperature of the atomic layer deposition chamber to be 65 - 75 °C;

[0023] Introduce trimethylaluminum and a water source into the atomic layer deposition chamber, and control the purge cycle times of the trimethylaluminum and the water source to form the aluminum oxide tunneling layer on the lead-based perovskite film light absorption layer.

[0024] Optionally, the step S4 includes:

[0025] Introduce diethylzinc and a water source into the atomic layer deposition chamber, and control the purge cycle times of the diethylzinc and the water source to form the zinc oxide semiconductor layer on the aluminum oxide tunneling layer.

[0026] Optionally, the step S5 includes:

[0027] Using a metal mask, an aluminum electrode with a thickness of 80 - 120 nm is thermally evaporated on the zinc oxide semiconductor layer as the source electrode and the drain electrode, forming the source / drain electrode layer.

[0028] Optionally, the channel length formed by the zinc oxide semiconductor layer and the source / drain electrode layer is 80 μm, and the width is 200 μm.

[0029] Advantages of the present invention: 1. In the present invention, an aluminum oxide tunneling layer (ultra-thin layer) is inserted at the heterojunction interface between the lead-based perovskite light absorption layer and the aluminum oxide tunneling layer as a carrier speed-limiting layer. At this time, the photo-generated carriers generated after light stimulation transfer more slowly between the heterojunctions due to the high potential barrier of the speed-limiting layer, making it difficult for the carriers to reach saturation due to accumulation at the interface potential barrier; the increase in the interface potential barrier also hinders the recombination of photo-generated carriers, greatly extending the storage time of the carriers. When the second stimulation is triggered, the current maintenance level is still relatively high and the potential difference at which the photo-generated carriers are separated at the heterojunction interface is relatively larger, so the post-synaptic current level is increased. By restricting the transfer speed and recombination rate of the carriers, the present invention can ultimately effectively solve the problem of easy generation of non-linear current signal response due to the limitation of the saturated photocurrent in the prior art, and improve the linearity of the opto-synaptic transistor. 2. In the present invention, an aluminum oxide tunneling layer is inserted at the heterojunction interface between the lead-based perovskite light absorption layer and the aluminum oxide tunneling layer as a surface modification layer. Since the surface modification layer can enable more zinc oxide to adhere to form a dense and uniform layered structure, avoiding the problem that the direct atomic deposition for preparing the zinc oxide film cannot completely cover the surface of the lead-based perovskite grains, effectively solving the problems of poor charge transport and increased interface defects caused by the non-uniformity of the zinc oxide semiconductor layer in the prior art.

[0030] In summary, the present invention constructs an ultra-thin aluminum oxide tunneling layer between the lead-based perovskite light absorption layer and the zinc oxide semiconductor layer, and uses the aluminum oxide tunneling layer to limit the transfer of photo-generated carriers, which can effectively delay the photocurrent saturation speed of the device, thereby improving the non-linearity of the opto-synaptic transistor device. Description of the Drawings

[0031] Figure 1 is a schematic structural diagram of a lead-based perovskite composite opto-synaptic transistor provided by a specific embodiment of the present invention;

[0032] Figure 2 is a schematic flow diagram of a preparation method of a lead-based perovskite composite opto-synaptic transistor provided by a specific embodiment of the present invention;

[0033] Figure 3 is a 3D structural diagram and energy level diagram of a lead-based perovskite composite opto-synaptic transistor provided by a specific embodiment of the present invention;

[0034] Figure 4It is a schematic diagram showing the variation of current with time after applying a light pulse to a lead-based perovskite composite opto-synaptic transistor provided by a specific embodiment of the present invention;

[0035] Figure 5 It is a schematic diagram showing the variation of current with time after applying a light pulse to a lead-based perovskite composite opto-synaptic transistor provided by the prior art. Detailed implementation manners

[0036] The present invention discloses a lead-based perovskite composite opto-synaptic transistor and its preparation method. Those skilled in the art can draw on the content of this article and appropriately improve the technical details to implement. It should be particularly noted that all similar substitutions and modifications are obvious to those skilled in the art, and they are all regarded as included in the present invention. The methods and applications of the present invention have been described through preferred embodiments. It is obvious that relevant personnel can make changes or appropriate alterations and combinations to the methods and applications described herein without departing from the content, spirit, and scope of the present invention to implement and apply the technology of the present invention.

[0037] Through research by the applicant, it is found that: in order to improve the performance and accuracy of digital recognition and image processing, linearity is crucial as an index for evaluating the accuracy and stability of the system. High linearity of the system can achieve precise classification and processing of input signals, significantly improving the accuracy of recognition and processing. In tasks such as handwritten digit recognition and image preprocessing, small changes in input signals may lead to large fluctuations in results. Low linearity may result in misclassification and unstable results. Therefore, enhancing the linearity of the system is very important for improving accuracy, stability, and robustness. Currently, most opto-synaptic devices mainly utilize the positive photoconductivity response characteristics of optical materials. However, due to the limitation of saturated photocurrent and some other factors (such as non-uniformity of the semiconductor layer), opto-synaptic devices are prone to generating non-linear current signal responses.

[0038] Therefore, an embodiment of the present invention provides a lead-based perovskite composite opto-synaptic transistor, as Figure 1As shown, the lead-based perovskite composite opto-synaptic transistor has a hierarchical structure, which sequentially includes from bottom to top: a silicon dioxide / silicon-based bottom layer 101, a lead-based perovskite light absorption layer 102, an aluminum oxide tunneling layer 103, a zinc oxide semiconductor layer 104, and a source / drain electrode layer 105. The source / drain electrode layer 105 includes a source electrode and a drain electrode respectively disposed on both sides of the upper surface of the zinc oxide semiconductor layer 104. The main component of the lead-based perovskite light absorption layer 102 is CsPbBr3. The aluminum oxide tunneling layer 103 is used to improve the adhesion of the zinc oxide semiconductor layer 104, thereby making the zinc oxide semiconductor layer 104 uniform and dense. Among them, the lead-based perovskite light absorption layer 102, the aluminum oxide tunneling layer 103, and the zinc oxide semiconductor layer 104 form a composite film layer. The high potential barrier of the aluminum oxide tunneling layer 103 restricts the transfer speed and recombination rate of photo-generated carriers, so as to reduce the light-induced recombination speed of the lead-based perovskite composite opto-synaptic transistor.

[0039] In this specific embodiment, the aluminum oxide tunneling layer 103 has an ultra-thin structure.

[0040] It should be noted that in the embodiment of the present invention, by adding the aluminum oxide tunneling layer 103 structure, on the one hand, it can rely on the good adhesion of aluminum oxide to both lead-based perovskite and zinc oxide to improve the density and uniformity of the zinc oxide semiconductor, thereby avoiding problems such as poor charge transport and increased interface defects, and improving the device quality. On the other hand, by using the aluminum oxide tunneling layer 103 as a carrier speed-limiting layer to limit photo-generated carriers, the saturation speed of photoconductivity can be effectively delayed, thereby improving the non-linearity of the device.

[0041] It is worth mentioning that by adding the aluminum oxide tunneling layer 103, during the light pulse process, photo-generated carriers; the synapse slowly decreases, and the carrier recombination is relatively slow, effectively improving the linearity.

[0042] The embodiment of the present invention also provides a preparation method of a lead-based perovskite composite opto-synaptic transistor, which is applied to the above-mentioned lead-based perovskite composite opto-synaptic transistor, as Figure 2 shown, the method includes:

[0043] Step S1: Dissolve lead bromide and cesium bromide in dimethyl sulfoxide according to a preset ratio to obtain a lead-based perovskite precursor solution.

[0044] In this specific embodiment, step S1 includes:

[0045] Dissolve lead bromide and cesium bromide in dimethyl sulfoxide according to a molar ratio of 1:1, and heat and stir at 70 °C for 2 hours to obtain a lead-based perovskite precursor solution; wherein, the concentration of the lead-based perovskite precursor solution is 0.08M.

[0046] It should be noted that the lead-based perovskite is CsPbBr3. As a light-absorbing material, CsPbBr3 has broad prospects in the application of opto-synaptic devices due to its unique optoelectronic properties.

[0047] Step S2: Spin-coat the lead-based perovskite precursor solution on the silica / silicon substrate to form a lead-based perovskite film; perform vacuum pumping on the lead-based perovskite film to remove excess solvent and obtain a lead-based perovskite film light-absorbing layer.

[0048] In this specific embodiment, before step S2, the method further includes:

[0049] Filter the lead-based perovskite precursor solution using a filter head with a pore size of 0.22 μm.

[0050] It should be noted that filtering the lead-based perovskite precursor solution reduces particulate matter and avoids unevenness during spin-coating due to particulate matter.

[0051] In this specific embodiment, before step S2, the method further includes:

[0052] Clean the silica / silicon substrate with acetone, isopropyl alcohol, and deionized water respectively; perform oxygen plasma treatment on the silica / silicon substrate to improve the surface hydrophilicity of the silica / silicon substrate; wherein, the silica / silicon substrate is n-type.

[0053] It should be noted that performing extraction treatment on the silica / silicon substrate ensures the spin-coating quality of the lead-based perovskite precursor solution, makes the film formation more uniform, and thus improves the device performance.

[0054] In this specific embodiment, step S2 includes:

[0055] Place the silica / silicon substrate in a nitrogen atmosphere and set the spin-coating speed to 3000 - 6000 rpm; drop the lead-based perovskite precursor solution preheated at 100 °C on the silica / silicon substrate and spin-coat to form a film;

[0056] Transfer the spin-coated silica / silicon substrate to a vacuum chamber for vacuum pumping for a first preset duration to remove excess solvent and obtain a lead-based perovskite film light-absorbing layer.

[0057] It should be noted that through the operations of this specific embodiment, the lead-based perovskite film light-absorbing layer can be made more uniform and have better performance.

[0058] Step S3: Deposit alumina on the lead-based perovskite film light-absorbing layer to form an alumina tunneling layer.

[0059] Among them, the adhesion of alumina to the photoabsorbing layer of the lead-based perovskite film is greater than that of zinc oxide to the photoabsorbing layer of the lead-based perovskite film. The high potential barrier of the alumina tunneling layer restricts the transfer speed and recombination rate of photo-generated carriers, reducing the photo-induced recombination speed of the lead-based perovskite composite photonic synapse transistor.

[0060] Step S4: Deposit zinc oxide on the alumina tunneling layer to form a zinc oxide semiconductor layer.

[0061] Among them, the adhesion of zinc oxide to the alumina tunneling layer is greater than that of zinc oxide to the photoabsorbing layer of the lead-based perovskite film.

[0062] It should be noted that by using the alumina tunneling layer as a surface modification layer, the adhesion of the zinc oxide semiconductor layer is effectively increased, and thus a more uniform and dense structure can be formed.

[0063] In this specific embodiment, step S3 includes:

[0064] Transfer the silica / silicon substrate and the photoabsorbing layer of the lead-based perovskite film to the atomic layer deposition chamber, and control the growth temperature of the atomic layer deposition chamber to be 65 - 75 °C;

[0065] Introduce trimethylaluminum and water source into the atomic layer deposition chamber, and control the purge cycle times of trimethylaluminum and water source to form an alumina tunneling layer on the photoabsorbing layer of the lead-based perovskite film.

[0066] Furthermore, step S4 includes:

[0067] Introduce diethylzinc and water source into the atomic layer deposition chamber, and control the purge cycle times of diethylzinc and water source to form a zinc oxide semiconductor layer on the alumina tunneling layer.

[0068] It should be noted that atomic layer deposition (ALD) is a technique for precisely controlling the film thickness and uniformity, suitable for preparing high-quality nanoscale films.

[0069] Step S5: Fabricate source and drain electrodes on both sides of the upper surface of the zinc oxide semiconductor layer to form a source / drain electrode layer.

[0070] In this specific embodiment, step S5 includes:

[0071] Use a metal mask template to thermally evaporate an 80 - 120 nm thick aluminum electrode on the zinc oxide semiconductor layer as the source and drain electrodes to form a source / drain electrode layer.

[0072] It should be noted that in other specific applications, other metal materials such as gold and silver can be used as electrodes.

[0073] In this specific embodiment, the channel length formed by the zinc oxide semiconductor layer and the source / drain electrode layer is 80 μm, and the width is 200 μm.

[0074] In a specific application, such as Figure 3 shown, Figure 3 (a) shows a schematic diagram of the device structure of a photon synaptic transistor based on a CsPbBr3 / Al2O3 / ZnO composite film (i.e., a composite film layer formed by a lead-based perovskite light absorption layer, an alumina tunneling layer, and a zinc oxide semiconductor layer). A CsPbBr3 film with an island structure is used as the light absorption layer on a silica substrate, and the Al2O3 / ZnO film wraps around the CsPbBr3 grains to form a CsPbBr3 / Al2O3 / ZnO composite film. Patterned aluminum metal serves as the source and drain electrodes on the composite film. As Figure 3 (b) shows, it is the energy level diagram of the CsPbBr3 / Al2O3 / ZnO composite transistor device. The minimum conduction band value and the maximum valence band value of CsPbBr3 and ZnO are -5.94 eV (-7.65 eV) and -3.55 eV (-4.3 eV) respectively, forming a type-II heterojunction. Al2O3 forms a blocking layer between CsPbBr3 and ZnO. Through such a structure, the transfer of photo-generated carriers can be effectively restricted, and the saturation speed of the device photocurrent can be effectively delayed, thereby improving the nonlinearity of the device.

[0075] In a specific application, a comparison is made between the lead-based perovskite composite photo-synaptic transistor with an alumina tunneling layer prepared in an embodiment of the present invention and the lead-based perovskite composite photo-synaptic transistor without an alumina tunneling layer in the prior art, as Figure 4 shown, Figure 4 is a schematic diagram showing the change of the device current over time after applying 40 light pulses in an embodiment of the present invention ( Figure 4 each small wave peak fluctuation in represents the application of one light pulse, because there will be a slight drop in the applied pulse current to form a wave peak), Figure 5 is a schematic diagram showing the change of the device current over time after applying 20 light pulses in the prior art (similarly to Figure 4 , one small wave peak represents the application of one light pulse). From the comparison between Figure 4 and Figure 5 , it can be seen that compared with the prior art, the light pulses applied in the embodiments of the present invention and the device current have a better linear relationship. Therefore, the high linearity of the embodiments of the present invention can achieve accurate classification and processing of input signals, significantly improving the accuracy of recognition and processing.

[0076] It is worth mentioning that Figure 4 when no pulse is applied in, the current of the device slowly decreases.

[0077] In the embodiment of the present invention, an aluminum oxide tunneling layer (ultra-thin layer) is inserted at the heterojunction interface between the lead-based perovskite light absorption layer and the aluminum oxide tunneling layer as a carrier speed-limiting layer. At this time, the photo-generated carriers generated after light stimulation transfer more slowly between the heterojunctions due to the high potential barrier of the speed-limiting layer, making it difficult for the carriers to reach saturation due to the accumulation at the interface potential barrier; the increase in the interface potential barrier also hinders the recombination of photo-generated carriers, greatly prolonging the storage time of the carriers. When the second stimulation is triggered, the current maintenance level is still relatively high and the potential difference at which the photo-generated carriers are separated at the heterojunction interface is relatively larger. Therefore, the post-synaptic current level is increased. In the embodiment of the present invention, by restricting the transfer speed and recombination rate of the carriers, the light-induced recombination speed of the lead-based perovskite composite photonic synaptic transistor is reduced, and finally the problem of non-linear current signal response easily generated due to the limitation of the saturated photocurrent in the prior art can be effectively solved, and the linearity of the photonic synaptic transistor is improved.

[0078] In the embodiment of the present invention, an aluminum oxide tunneling layer is inserted at the heterojunction interface between the lead-based perovskite light absorption layer and the aluminum oxide tunneling layer as a surface modification layer. Since the surface modification layer can enable more zinc oxide to adhere to form a dense and uniform layered structure, it avoids the problem that the direct atomic deposition for preparing the zinc oxide film cannot completely cover the surface of the lead-based perovskite grains, and effectively solves the problems of poor charge transport and increased interface defects caused by the non-uniformity of the zinc oxide semiconductor layer in the prior art.

[0079] In summary, the embodiment of the present invention uses the aluminum oxide tunneling layer to limit the transfer of photo-generated carriers, which can effectively delay the saturation speed of the photoconductivity, thereby improving the non-linearity of the photonic synaptic transistor device.

[0080] It should be noted that in this article, relational terms such as 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 actual relationship or order between these entities or operations. Moreover, the term "comprising", "including" or any other variant thereof is intended to cover non-exclusive inclusion, so that a process, method, article or device comprising a series of elements not only includes those elements, but also includes other elements not expressly listed, or also includes elements inherent to such process, method, article or device. Without further limitation, an element defined by the statement "comprising an..." does not exclude the existence of additional identical elements in the process, method, article or device comprising the element.

[0081] Each embodiment in this specification is described in a related manner. For the same or similar parts among the embodiments, reference can be made to each other, and the key point of each embodiment is to illustrate the differences from other embodiments. In particular, for the system embodiment, since it is basically similar to the method embodiment, the description is relatively simple, and for the related parts, reference can be made to the partial description of the method embodiment.

[0082] The above are only the preferred embodiments of the present invention, and are not intended to limit the protection scope of the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principle of the present invention are all included in the protection scope of the present invention.

Claims

1. A lead-based perovskite composite opto-synaptic transistor, characterized in that, The lead-based perovskite composite photonic synapse transistor has a hierarchical structure, which sequentially includes from bottom to top: a silicon dioxide / silicon-based substrate, a lead-based perovskite light absorption layer, an aluminum oxide tunneling layer, a zinc oxide semiconductor layer, and a source / drain electrode layer. The source / drain electrode layer includes a source electrode and a drain electrode respectively disposed on both sides of the upper surface of the zinc oxide semiconductor layer. The main component of the lead-based perovskite light absorption layer is CsPbBr3. The aluminum oxide tunneling layer is used to improve the adhesion of the zinc oxide semiconductor layer, so that the zinc oxide semiconductor layer is uniform and dense. Among them, the lead-based perovskite light absorption layer, the aluminum oxide tunneling layer, and the zinc oxide semiconductor layer form a composite film layer. The high potential barrier of the aluminum oxide tunneling layer limits the transfer speed and recombination rate of photo-generated carriers to slow down the speed at which the lead-based perovskite composite photonic synapse transistor reaches photocurrent saturation.

2. A preparation method of a lead-based perovskite composite optosynaptic transistor, characterized in that, Applied to the lead-based perovskite composite photonic synapse transistor of the above claim 1, the method includes: Step S1: Dissolve lead bromide and cesium bromide in dimethyl sulfoxide according to a preset ratio to obtain a lead-based perovskite precursor solution. Step S2: Spin-coat the lead-based perovskite precursor solution on a silicon dioxide / silicon substrate to form a lead-based perovskite film. Vacuum pump the lead-based perovskite film to remove excess solvent to obtain a lead-based perovskite film light absorption layer. Step S3: Deposit aluminum oxide on the lead-based perovskite film light absorption layer to form the aluminum oxide tunneling layer. Among them, the adhesion of the aluminum oxide to the lead-based perovskite film light absorption layer is greater than the adhesion of the zinc oxide to the lead-based perovskite film light absorption layer. The high potential barrier of the aluminum oxide tunneling layer limits the transfer speed and recombination rate of photo-generated carriers to slow down the speed at which the lead-based perovskite composite photonic synapse transistor reaches photocurrent saturation. Step S4: Deposit zinc oxide on the aluminum oxide tunneling layer to form the zinc oxide semiconductor layer. Among them, the adhesion of the zinc oxide to the aluminum oxide tunneling layer is greater than the adhesion of the zinc oxide to the lead-based perovskite film light absorption layer. Step S5: Prepare a source electrode and a drain electrode on both sides of the upper surface of the zinc oxide semiconductor layer to form a source / drain electrode layer.

3. The preparation method of the lead-based perovskite composite opto-synaptic transistor according to claim 2, wherein The step S1 includes: Dissolve lead bromide and cesium bromide in dimethyl sulfoxide according to a molar ratio of 1:1, and heat and stir at 70 °C for 2 hours to obtain the lead-based perovskite precursor solution. Among them, the concentration of the lead-based perovskite precursor solution is 0.08M.

4. The preparation method of the lead-based perovskite composite optosynaptic transistor according to claim 2, wherein Before the step S2, the method further includes: Filter the lead-based perovskite precursor solution with a filter head having a pore size of 0.22 μm.

5. The preparation method of the lead-based perovskite composite opto-synaptic transistor according to claim 2, characterized in that Before the step S2, the method further includes: Clean the silicon dioxide / silicon substrate with acetone, isopropyl alcohol, and deionized water respectively. Treat the silicon dioxide / silicon substrate with oxygen plasma to improve the surface hydrophilicity of the silicon dioxide / silicon substrate. Among them, the silicon dioxide / silicon substrate is n-type.

6. The preparation method of the lead-based perovskite composite opto-synaptic transistor according to claim 2, wherein, The step S2 includes: Place the silica / silicon substrate in a nitrogen atmosphere and set the spin coating speed to 3000 - 6000 rpm; drop the lead-based perovskite precursor solution preheated to 100 °C onto the silica / silicon substrate and spin coat to form a film. Transfer the spin-coated silica / silicon substrate to a vacuum chamber for vacuum pumping for a first preset duration to remove excess solvent and obtain the lead-based perovskite film light absorption layer.

7. The method for preparing a lead-based perovskite composite optosynaptic transistor according to claim 2, wherein Step S3 includes: Transfer the silica / silicon substrate and the lead-based perovskite film light absorption layer to an atomic layer deposition chamber and control the growth temperature of the atomic layer deposition chamber to be 65 - 75 °C. Introduce trimethylaluminum and water source into the atomic layer deposition chamber and control the purge cycle times of the trimethylaluminum and water source to form the aluminum oxide tunneling layer on the lead-based perovskite film light absorption layer.

8. The preparation method of the lead-based perovskite composite optosynaptic transistor according to claim 7, characterized in that, Step S4 includes: Introduce diethylzinc and water source into the atomic layer deposition chamber and control the purge cycle times of the diethylzinc and water source to form the zinc oxide semiconductor layer on the aluminum oxide tunneling layer.

9. The preparation method of the lead-based perovskite composite opto-synaptic transistor according to claim 2, wherein Step S5 includes: Thermally evaporate an 80 - 120 nm thick aluminum electrode on the zinc oxide semiconductor layer using a metal mask template as the source electrode and the drain electrode to form the source / drain electrode layer.

10. The method for preparing a lead-based perovskite composite optosynaptic transistor according to claim 1, wherein The channel length formed by the zinc oxide semiconductor layer and the source / drain electrode layer is 80 μm, and the width is 200 μm.

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