Full-light-control positive and negative photoresponse device capable of adjusting grid voltage and preparation method of full-light-control positive and negative photoresponse device

Abstract

The invention relates to a full-light-control positive and negative photoresponse device capable of adjusting grid voltage and a preparation method of the full-light-control positive and negative photoresponse device. The positive and negative photoresponse device comprises a substrate, a source electrode, a drain electrode and a zinc oxide layer, the source electrode, the drain electrode and the zinc oxide layer are arranged on the surface of the substrate, the zinc oxide layer is arranged between the source electrode and the drain electrode, an MAPbBr3 thin film is arranged on the surface of the zinc oxide layer, and a grid electrode is further arranged on the surface, away from the MAPbBr3 thin film, of the substrate; the light response threshold value of the positive and negative light response device is greater than or equal to 5 [mu] W / cm < 2 >. According to the positive and negative photoresponse device, full light control can be achieved through light intensity changes, the voltage of the grid electrode is adjusted to achieve photoresponse current modulation, the sensitivity of photoresponse to the light intensity is high, and therefore the high device precision requirement can be met.

Description

Technical Field

[0001] The present invention relates to the field of semiconductor technology, and in particular to a fully light-controlled gate voltage-adjustable positive and negative light response device and a preparation method thereof. Background Art

[0002] In semiconductor devices that can achieve positive and negative photoresponses, usually a single wavelength of light can only achieve a single photoresponse, and the other photoresponse is generally achieved by electrical stimulation. It is difficult to achieve both positive and negative photoresponses with one light source. In addition, the radiation intensity of the required light source needs to reach 1×10 -3 W / cm 2 The above means that the light response sensitivity of the device is low. The modulation method of the response size also depends on the change of light intensity or the change of source-drain voltage. Therefore, it is necessary to provide a semiconductor device that can not only realize full light control, but also modulate the light response by applying a gate voltage and has high light response sensitivity. Summary of the invention

[0003] Based on this, it is necessary to provide a fully light-controlled positive and negative light-response device with adjustable gate voltage and a preparation method thereof to address the above problems; the positive and negative light-response device can not only achieve full light control by changing the light intensity and adjust the gate voltage to achieve light-response current modulation, but also the light response is highly sensitive to the light intensity, thereby being able to meet higher device precision requirements.

[0004] A positive and negative light response device, comprising a substrate and a source electrode, a drain electrode and a zinc oxide layer arranged on the surface of the substrate, wherein the zinc oxide layer is arranged between the source electrode and the drain electrode, a MAPbBr3 film is arranged on the surface of the zinc oxide layer, and a gate is also arranged on the surface of the substrate away from the MAPbBr3 film;

[0005] The light response threshold of the positive and negative light response device is greater than or equal to 5 μW / cm 2 .

[0006] In one embodiment, the base includes a silicon dioxide layer and a silicon substrate, and the silicon dioxide layer is disposed between the silicon substrate and the zinc oxide layer.

[0007] In one embodiment, the silicon dioxide layer has a thickness of 100 nm-300 nm and a resistivity of less than 0.01 Ω·cm.

[0008] In one of the embodiments, the silicon substrate is selected from a P-type heavily doped silicon substrate.

[0009] In one of the embodiments, a passivation layer is further provided on the surface of the MAPbBr3 film.

[0010] In one embodiment, the material of the passivation layer is selected from n-octylamine hydrobromide.

[0011] A method for preparing the positive and negative light response device as described above comprises the following steps:

[0012] A source electrode, a drain electrode and a zinc oxide layer are respectively prepared on the surface of the substrate by a mask method, and the prepared surface is subjected to a hydrophilic treatment;

[0013] Using a mask to selectively hydrophobize the surface after hydrophilic treatment, so that hydrophilic areas and hydrophobic areas are formed on the surface;

[0014] A MAPbBr3 precursor solution is prepared, the MAPbBr3 precursor solution is placed on the surface after the selective hydrophobic treatment, and an anti-solvent is added to the MAPbBr3 precursor solution to form a MAPbBr3 film in the hydrophilic region;

[0015] A gate is prepared on the surface of the substrate away from the MAPbBr3 film to obtain the positive and negative light response device.

[0016] In one embodiment, the hydrophilic treatment is selected from oxygen plasma surface treatment, and the power of the oxygen plasma surface treatment is 40W-60W, and the time is 10s-30s.

[0017] In one embodiment, the selective hydrophobic treatment includes: masking the surface after the hydrophilic treatment, first depositing silicon dioxide, and then using a fluorine-containing silane treatment agent to perform a silanization reaction to form the hydrophobic area, and the surface covered by the mask is the hydrophilic area.

[0018] In one embodiment, the MAPbBr3 precursor solution includes methyl ammonium bromide, lead bromide and a solvent, wherein the molar ratio of the methyl ammonium bromide to the lead bromide is 1:0.8-1.2:1;

[0019] And / or, after adding an anti-solvent to the MAPbBr3 precursor solution, annealing is performed.

[0020] In the positive and negative photoresponse device described in the present invention, the synergistic effect of the zinc oxide layer and the MAPbBr3 film is utilized. On the one hand, positive and negative bidirectional photoresponses are achieved by using the same light source with different light intensities, thereby realizing full light control of the device; on the other hand, by applying a back gate voltage, the regulation of the heterojunction interface carriers can be realized, thereby realizing the modulation of the photoresponse current. At the same time, the photoresponse threshold of the positive and negative photoresponse device is significantly reduced. Compared with the traditional thin film device that can achieve positive and negative photoresponse, the radiation intensity of the light source is reduced by three orders of magnitude, and the sensitivity is higher, so that higher device precision requirements can be met. In addition, the positive and negative photoresponse device provided by the present invention has a simple structure and is easy to prepare. Therefore, the positive and negative photoresponse device provided by the present invention has a wide range of application potentials in the fields of photoelectric detection and the like. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0022] Figure 1 Schematic diagram of the cross-sectional structure of a positive and negative light response device in one embodiment of the present invention;

[0023] Figure 2 This is a graph showing the variation of the light response of the positive and negative light response devices obtained in Example 1 under different gate voltage conditions with the light intensity of a 365nm light source;

[0024] Figure 3 This is a graph showing how the light response of the positive and negative light response devices prepared in Example 1 changes with the light intensity of a 555nm light source under different gate voltage conditions.

[0025] Among them, 10, base; 101, silicon substrate; 102, silicon dioxide layer; 20, source electrode; 30, drain electrode; 40, zinc oxide layer; 50, MAPbBr3 film; 60, gate; 70, passivation layer. DETAILED DESCRIPTION

[0026] For ease of understanding of the present invention, the present invention will be described in more detail below. However, it should be understood that the present invention can be implemented in many different forms and is not limited to the embodiments or examples described herein. On the contrary, the purpose of providing these embodiments or examples is to make the understanding of the disclosure of the present invention more thorough and comprehensive.

[0027] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those generally understood by those skilled in the art of the present invention. The terms used herein in the specification of the present invention are only for the purpose of describing specific implementation methods or embodiments, and are not intended to limit the present invention. The optional scope of the term "and / or" used herein includes any one of two or more related listed items, and also includes any and all combinations of related listed items, and the combinations include any two related listed items, any more related listed items, or all related listed items.

[0028] Combination Figure 1 , which is a schematic diagram of the cross-sectional structure of a positive and negative light response device in one embodiment of the present invention, the positive and negative light response device comprises a substrate 10 and a source electrode 20, a drain electrode 30 and a zinc oxide layer 40 arranged on the surface of the substrate 10, wherein the zinc oxide layer 40 is arranged between the source electrode 20 and the drain electrode 30, a MAPbBr3 film 50 is arranged on the surface of the zinc oxide layer 40, and a gate 60 is also arranged on the surface of the substrate 10 away from the MAPbBr3 film 50; the light response threshold of the positive and negative light response device is greater than or equal to 5μW / cm 2 .

[0029] In the positive and negative light response device described in the present invention, the synergistic effect of the zinc oxide layer 40 and the MAPbBr3 film 50 is utilized. On the one hand, positive and negative bidirectional light responses are achieved through the same light source with different light intensities, thereby realizing full light control of the device; on the other hand, the regulation of heterojunction interface carriers can be achieved by applying a back gate voltage, thereby realizing modulation of the light response current. At the same time, the light response threshold of the positive and negative light response device is significantly reduced. Compared with the traditional thin film device that can achieve positive and negative light response, the radiation intensity of the light source is reduced by three orders of magnitude, and the sensitivity is higher, so that it can meet the higher device precision requirements.

[0030] In one embodiment of the present invention, the base 10 includes a silicon dioxide layer 102 and a silicon substrate 101 , and the silicon dioxide layer 102 is disposed between the silicon substrate 101 and the zinc oxide layer 40 .

[0031] In one embodiment of the present invention, the thickness of the silicon dioxide layer 102 is 100 nm-300 nm, including but not limited to any point value among 100 nm, 200 nm, 300 nm or any range value between the two; the resistivity is less than 0.01 Ω·cm.

[0032] In one embodiment of the present invention, the silicon substrate 101 includes but is not limited to a P-type heavily doped silicon substrate, and is preferably a P-type heavily doped silicon substrate.

[0033] It can be understood that the source electrode 20, the drain electrode 30 and the substrate 10 form a channel structure, wherein the substrate 10 is the bottom surface of the channel, the source electrode 20 and the drain electrode 30 are the sides of the channel, and the zinc oxide layer 40 at least fills the channel. Preferably, the maximum thickness of the zinc oxide layer 40 is greater than the thickness of the source electrode 20 or the drain electrode 30. The present invention does not limit the sizes of the silicon substrate 101, the source electrode 20, the drain electrode 30 and the zinc oxide layer 40.

[0034] In one embodiment of the present invention, the source electrode 20 and the drain electrode 30 are independently selected from a composite layer of a chromium metal layer and a platinum metal layer, wherein the chromium metal layer is arranged between the platinum metal layer and the substrate 10, and preferably, the thickness ratio of the chromium metal layer to the platinum metal layer is 5:30-10:50.

[0035] In one embodiment of the present invention, a passivation layer 70 is further provided on the surface of the MAPbBr3 film 50, which is beneficial to enhancing the environmental stability of the positive and negative light response device of the present invention.

[0036] In one embodiment of the present invention, the material of the passivation layer 70 includes but is not limited to n-octylamine hydrobromide, preferably n-octylamine hydrobromide. It is understandable that the present invention does not limit the thickness of the passivation layer 70.

[0037] The present invention also provides a method for preparing the positive and negative light response device as described above, comprising the following steps:

[0038] S1, preparing a source electrode, a drain electrode and a zinc oxide layer on the surface of a substrate respectively by a mask method, and performing a hydrophilic treatment on the prepared surface;

[0039] S2, using a mask to selectively hydrophobize the surface after the hydrophilic treatment, so that a hydrophilic area and a hydrophobic area are formed on the surface;

[0040] S3, preparing a MAPbBr3 precursor solution, placing the MAPbBr3 precursor solution on the surface after the selective hydrophobic treatment, adding an anti-solvent to the MAPbBr3 precursor solution, so that a MAPbBr3 film is formed in the hydrophilic region;

[0041] S4, preparing a gate on the substrate surface away from the MAPbBr3 film to obtain the positive and negative light response device.

[0042] In step S1, a composite substrate composed of silicon dioxide and P-type heavily doped silicon is preferably used. Specifically, before the source electrode, the drain electrode and the zinc oxide layer are prepared by a mask method, the substrate is firstly formed along the crystal direction. <100> The substrate is cut and then immersed in an acetone solution and ultrasonically cleaned. After cleaning, it is rinsed with isopropyl alcohol and deionized water respectively, and finally the surface is dried with nitrogen to remove organic pollutants and impurity particles on the substrate surface.

[0043] In one embodiment of the present invention, the substrate is preferably subjected to oxygen plasma surface treatment to obtain a substrate interface with good hydrophilicity.

[0044] In one embodiment of the present invention, compared with traditional source electrodes and drain electrodes, the source electrodes and drain electrodes prepared by the present invention are longer, which is beneficial to avoid the connection between the pad part and the channel part when the MAPbBr3 film is subsequently prepared.

[0045] In one embodiment of the present invention, after the substrate surface is covered with a mask, a sputtering process is preferably used to prepare the source electrode and the drain electrode. Specifically, a chromium metal layer is sputtered first, and then a platinum metal layer is sputtered to form a composite layer as an electrode.

[0046] It should be noted that the surfaces of the source electrode and the drain electrode can be subjected to a first hydrophilic treatment, and then the surface of the zinc oxide layer can be subjected to a second hydrophilic treatment. Alternatively, the surfaces of the source electrode, the drain electrode and the zinc oxide layer can be directly subjected to a hydrophilic treatment.

[0047] In one embodiment of the present invention, the hydrophilic treatment is selected from oxygen plasma surface treatment, and the power of the oxygen plasma surface treatment is 40W-50W, and the time is 10s-30s.

[0048] In step S2 and step S3, hydrophilic and hydrophobic regions are formed on the surface through selective hydrophobic treatment. When a MAPbBr3 precursor solution is used at the same time, the MAPbBr3 precursor solution selectively adheres to the hydrophilic region but not to the hydrophobic region, thereby achieving the localized growth of MAPbBr3 crystals. The preparation method provided by the present invention is not only beneficial to reducing the lattice defects of MAPbBr3 crystals, but also the preparation process is simple and fast, which is beneficial to the further large-scale arraying of devices.

[0049] In one embodiment of the present invention, the selective hydrophobic treatment includes: masking the surface after the hydrophilic treatment, preferably using a sputtering process to deposit silicon dioxide, so that silicon dioxide is attached to the surface not covered by the mask, and then using a fluorine-containing silane treatment agent to react with the silicon dioxide attached to the surface to form a stable Si-O-Si bond, thereby achieving selective hydrophobicity.

[0050] Preferably, the fluorine-containing silane treating agent includes but is not limited to 1H,1H,2H,2H-perfluorodecyltriethoxysilane, preferably 1H,1H,2H,2H-perfluorodecyltriethoxysilane.

[0051] In one embodiment of the present invention, silicon dioxide is deposited by sputtering process, and after silicon dioxide is attached to the surface not covered by the mask, a fluorine-containing silane treatment agent is continuously coated. In a vacuum environment, the fluorine-containing silane treatment agent evaporates and fills the reaction container. After sufficient reaction, the selective hydrophobic treatment is completed.

[0052] It is understandable that the present invention does not limit the specific mask plate size used in the above-mentioned mask process. Those skilled in the art can select a mask plate of corresponding size according to actual product requirements, or design a mask plate by themselves; in the above-mentioned preparation steps using the mask process, demolding is included. The present invention does not limit the specific process of demolding, and the existing process can be used, for example: first soaking in acetone solution, preferably performing ultrasonic treatment while soaking, which is beneficial to improving the stripping efficiency of the colloid, and then rinsing with isopropyl alcohol and deionized water in turn, and blowing the surface with nitrogen. More preferably, heating can be used to remove water vapor attached to the surface.

[0053] In one embodiment of the present invention, the MAPbBr3 precursor solution includes methylammonium bromide (MABr), lead bromide (PbBr2) and a solvent, wherein the molar ratio of the methylammonium bromide to the lead bromide is 1:0.8-1.2:1, including but not limited to any point value among 1:0.8, 1:0.9, 1:1, 1.1:1, 1.2:1 or any range value between two of them.

[0054] The solvent includes but is not limited to at least one of N,N-dimethylacetamide (DMF) and dimethyl sulfoxide (DMSO), and is preferably a mixed solution of N,N-dimethylacetamide (DMF) and dimethyl sulfoxide (DMSO).

[0055] In one embodiment of the present invention, the MAPbBr3 precursor solution is preferably placed on a selectively hydrophobic treated surface in an anhydrous and oxygen-free environment, and then an antisolvent is added to the MAPbBr3 precursor solution and annealed to transform the MAPbBr3 precursor solution into a crystal, thereby forming a MAPbBr3 film in the hydrophilic region.

[0056] Wherein, the anti-solvent includes but is not limited to ethyl acetate, preferably ethyl acetate.

[0057] In one embodiment of the present invention, after adding the anti-solvent to the MAPbBr3 precursor solution, annealing is preferably performed, the annealing temperature is preferably 80°C-100°C, and the annealing time is preferably 5min-10min.

[0058] In one embodiment of the present invention, it is preferred to further prepare a passivation layer on the surface of the MAPbBr3 film, which is beneficial to enhancing the environmental stability of the positive and negative light response devices.

[0059] The material of the passivation layer includes but is not limited to n-octylamine hydrobromide, preferably n-octylamine hydrobromide. It is understandable that the present invention does not limit the specific preparation process of the passivation layer, and the existing process can be used, which will not be described in detail in the present invention.

[0060] In step S4, the present invention does not limit the specific preparation process of the gate, and the existing process can be used, which will not be described in detail in the present invention.

[0061] The following specific examples will further illustrate the fully light-controlled gate voltage-adjustable positive and negative light-responsive device and its preparation method. However, those skilled in the art will understand that the following examples are only used to illustrate the present invention and should not be considered to limit the scope of the present invention. If no specific conditions are specified in the examples, the conventional conditions or the conditions recommended by the manufacturer are followed. The reagents or instruments used without indicating the manufacturer are all conventional products that can be purchased commercially.

[0062] It should be noted that the following embodiments and comparative examples all use the same mask process. Specifically, the first mask is used to prepare the source electrode and the drain electrode. The size of the first mask is 1.7 cm×1.7 cm. There are a total of 20 groups of channels in the first mask. The channel size is 4950μm×30μm×50μm, and the pad size in the channel is 300μm×300μm. The first mask is a dark field mask; the second mask is used to prepare the zinc oxide layer, and the second mask is a light and dark field mask; the third mask is used for selective hydrophobic treatment, and the third mask is a light and dark field mask.

[0063] Example 1

[0064] Select SiO2 / p + Si insulating substrate, wherein the thickness of the SiO2 layer is 300nm and the resistivity is less than 0.01Ω·cm. <100> Cut into several 2×2cm substrate pieces. Soak them in acetone solution and use an ultrasonic cleaner to clean for 5 minutes. After that, rinse them with isopropyl alcohol and deionized water respectively, and then blow dry the surface with nitrogen to remove organic pollutants and impurity particles. Then, use a plasma cleaner to perform oxygen plasma surface treatment with a power of 50W and a time of 20s to obtain a substrate interface with good hydrophilicity.

[0065] Place the substrate on a glue spreader, spin-coat s1813 positive photoresist at 500rpm / s×5s and 4000rpm / s×60s, and then place the substrate on a heating table at 115℃ for 1min. Then, use a UV photolithography machine and the first mask to expose the substrate for 20s. Subsequently, use zx238 developer for 12s of development, quickly rinse with deionized water for 10s after taking it out, and then blow dry the surface with nitrogen. Place the developed substrate in a magnetron sputtering device to prepare a 10nm thick Cr layer and a 40nm thick Pt layer in turn. After the end, soak it in an acetone solution for degumming, then rinse it with isopropyltone and deionized water respectively, and then blow dry the surface with nitrogen. Then, use a plasma cleaner again to perform oxygen plasma surface treatment with a power of 50W and a time of 20s to obtain a substrate interface with good hydrophilicity.

[0066] The substrate was placed on a coating machine, and NR9-1500PY negative photoresist was spin-coated at 500rpm / s×10s and 4000rpm / s×40s. Then, the substrate was placed on a heating table at 150℃ for 1min. Then, using a UV photolithography machine and a second mask, the electrode pattern of the previous layer was aligned with the mask pattern of this layer under a microscope, and the substrate was exposed to UV light for 40s. Then, the substrate was placed on a heating table at 100℃ for 1min. Subsequently, RD6 developer was used for 12s of development operation. After taking it out, it was quickly rinsed with deionized water for 10s, and then the surface was dried with nitrogen. The developed substrate was placed in a magnetron sputtering device and ZnO with a thickness of 70nm was sputtered. After completion, it was immersed in an acetone solution for degumming, and then rinsed with isopropyl ketone and deionized water respectively, and then the surface was dried with nitrogen. Then, a plasma cleaner was used again for oxygen plasma surface treatment with a power of 50W and a time of 10s.

[0067] Place the substrate on a coating machine and spin-coat s1813 positive photoresist at 500rpm / s×5s and 4000rpm / s×60s. Then place the substrate on a heating table at 115°C and dry for 1 minute. Then, use a UV photolithography machine and a third mask to expose the substrate to ultraviolet light for 20 seconds. Subsequently, use zx238 developer for 40 seconds of development. After taking it out, quickly rinse it with deionized water for 10 seconds, and then blow dry the surface with nitrogen. Place the developed substrate in a magnetron sputtering device and sputter 50nm of SiO2. Then, use a plasma cleaner again to perform oxygen plasma surface treatment with a power of 50W and a time of 10s.

[0068] Place the substrate on the dryer tray, place a glass slide in the center of the dryer tray, drop 5μL of 1H,1H,2H,2H-perfluorodecyltriethoxysilane, evacuate the dryer to allow the silane to evaporate and fill the dryer, place for 10 hours, and perform hydrophobic treatment. After the end, soak the substrate in acetone solution for degumming, then rinse with isopropyl acetone and deionized water respectively, then blow dry the surface with nitrogen, and heat on a 120℃ hot plate for 3 minutes to completely remove the water vapor attached to it.

[0069] In a nitrogen glove box, use an electronic analytical balance to weigh 112.0 mg of MABr and 367.0 mg of PbBr2, where the molar ratio of MABr to PbBr2 is 1:1, add 1 mL of DMF:DMSO = 4:1 solvent, stir at 500 rpm / s on a magnetic stirrer for 2 hours until a clear, transparent 1M MAPbBr3 precursor solution is obtained for use. In a nitrogen glove box, place the substrate on a homopolymerizer, drip 80 μL of the precursor solution, spin coat at 4000 rpm / s for 40 seconds, and quickly drip 200 μL of anti-solvent ethyl acetate vertically above the substrate at the tenth second. After the spin coating is completed, place the substrate on a 100°C hot plate for annealing for 10 minutes to obtain a MAPbBr3 film. After the substrate was cooled, it was placed on a coater, 100 μL of n-octylamine hydrobromide was added, and spin-coated at 4000 rpm / s for 20 seconds, followed by annealing on a hot plate at 100° C. for 1 minute to obtain a passivation layer.

[0070] An area is selected on the surface of the substrate, and the silicon oxide layer is removed by a silicon knife to expose the highly doped silicon layer of the substrate as a gate, thereby obtaining a positive and negative light response device.

[0071] Apply 1V source-drain voltage to the device. After the device current stabilizes, use 365nm / 555nm light sources with different light intensities to irradiate the device for about 10s. A negative light response is generated under weak light, that is, the current decreases compared to the initial dark current. As the light intensity continues to increase, the negative light response first increases, then decreases, and finally turns into a positive light response. The gate voltages of -20V, -10V, 0V, 10V, and 20V are applied through the back gate for testing. The results are as follows: Figure 2 and Figure 3 As shown in the figure, it can be seen that negative gate voltage weakens negative and positive photoresponses, while positive gate voltage enhances negative and positive photoresponses. This proves that the positive and negative photoresponse device prepared in this embodiment not only realizes full light control of photoresponse conversion, but also realizes the modulation of the gate voltage on its photoresponse intensity. At the same time, the photoresponse threshold is as low as 5μW / cm 2 , proving that it has high photoresponse conversion sensitivity.

[0072] Example 2

[0073] Compared with Example 1, Example 2 differs in that the solvent of the mixed solution of DMF and DMSO in preparing the MAPbBr3 precursor solution is replaced with an equal amount of pure DMSO solution, and the steps of spin coating the perovskite layer are: spin coating at 5000 rpm / s for 40 seconds, adding anti-solvent in the 5th second, and no annealing and spin coating of the passivation layer are performed, and the gate is directly prepared to obtain a positive and negative light response device.

[0074] After the solvent was replaced from a mixed solution of DMF and DMSO to a pure DMSO solution, the crystal growth rate slowed down during the spin coating process due to the increase in the boiling point of the solvent, thereby greatly improving the quality and significantly improving the device reproducibility.

[0075] The technical features of the above-described embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0076] The above-mentioned embodiments only express several implementation methods of the present invention, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the invention patent. It should be pointed out that, for ordinary technicians in this field, several variations and improvements can be made without departing from the concept of the present invention, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the patent of the present invention shall be subject to the attached claims.

Claims

1. A positive and negative light response device, characterized in that: It comprises a substrate and a source electrode, a drain electrode and a zinc oxide layer arranged on the surface of the substrate, wherein the zinc oxide layer is arranged between the source electrode and the drain electrode, a MAPbBr3 film is arranged on the surface of the zinc oxide layer, and a gate is also arranged on the surface of the substrate away from the MAPbBr3 film; The light response threshold of the positive and negative light response device is greater than or equal to 5 μW / cm 2 .

2. The positive and negative light response device according to claim 1, characterized in that: The base comprises a silicon dioxide layer and a silicon substrate, wherein the silicon dioxide layer is arranged between the silicon substrate and the zinc oxide layer.

3. The positive and negative light response device according to claim 2, characterized in that: The silicon dioxide layer has a thickness of 100 nm to 300 nm and a resistivity of less than 0.01 Ω·cm.

4. The positive and negative light response device according to claim 2, characterized in that: The silicon substrate is selected from a P-type heavily doped silicon substrate.

5. The positive and negative light response device according to claim 1, characterized in that: A passivation layer is also provided on the surface of the MAPbBr3 film.

6. The positive and negative light response device according to claim 5, characterized in that: The material of the passivation layer is selected from n-octylamine hydrobromide.

7. A method for preparing a positive and negative light response device as claimed in any one of claims 1 to 6, characterized in that: The steps include: A source electrode, a drain electrode and a zinc oxide layer are respectively prepared on the surface of the substrate by a mask method, and the prepared surface is subjected to a hydrophilic treatment; Using a mask to selectively hydrophobize the surface after hydrophilic treatment, so that hydrophilic areas and hydrophobic areas are formed on the surface; A MAPbBr3 precursor solution is prepared, the MAPbBr3 precursor solution is placed on the surface after the selective hydrophobic treatment, and an anti-solvent is added to the MAPbBr3 precursor solution to form a MAPbBr3 film in the hydrophilic region; A gate is prepared on the surface of the substrate away from the MAPbBr3 film to obtain the positive and negative light response device.

8. The preparation method according to claim 7, characterized in that: The hydrophilic treatment is selected from oxygen plasma surface treatment, the power of the oxygen plasma surface treatment is 40W-60W, and the time is 10s-30s.

9. The preparation method according to claim 7, characterized in that: The selective hydrophobic treatment includes: masking the surface after the hydrophilic treatment, first depositing silicon dioxide, and then using a fluorine-containing silane treatment agent to perform a silanization reaction to form the hydrophobic area, and the surface covered by the mask is the hydrophilic area.

10. The preparation method according to claim 7, characterized in that: The MAPbBr3 precursor solution includes methyl ammonium bromide, lead bromide and a solvent, wherein the molar ratio of the methyl ammonium bromide to the lead bromide is 1:0.8-1.2:1; And / or, after adding an anti-solvent to the MAPbBr3 precursor solution, annealing is performed.

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