Self-powered polarized photoelectric detector, preparation method thereof and polarization ratio regulation and control method of self-powered polarized photoelectric detector

Abstract

The invention provides a self-powered polarized photoelectric detector, a preparation method thereof and a method for regulating and controlling the polarization ratio of the self-powered polarized photoelectric detector. The structure of the self-powered polarized photoelectric detector comprises a conductive substrate layer, a two-dimensional perovskite ferroelectric film layer, a semiconductor material layer and a metal top electrode layer from bottom to top. The two-dimensional perovskite ferroelectric film layer and the semiconductor material layer can form a heterojunction with polarization property. Different polarization voltages are applied to the polarization photoelectric detector, the intensity of an electric field built in the two-dimensional perovskite ferroelectric film heterojunction is regulated and controlled, and the polarization ratio of the polarization sensitive photoelectric detector is dynamically regulated and controlled. The invention provides a convenient method for dynamically regulating and controlling the polarization ratio of the polarization sensitive photoelectric detector by using a ferroelectric-pyroelectric electro-optical electronic effect, and the regulation and control of the polarization ratio are realized on the same polarization device.

Description

Technical Field

[0001] The invention relates to the technical field of polarization photoelectric detectors, in particular to a self-powered polarization photoelectric detector, a preparation method thereof and a method for regulating and controlling a polarization ratio thereof. Background Art

[0002] Polarization-sensitive photodetectors based on anisotropic semiconductors have attracted much attention in the fields of polarization imaging, optical radar, remote sensing, target recognition, optical communications, and biomedicine. They provide new degrees of freedom by distinguishing and analyzing the polarization state of light, improving detection accuracy and sensitivity in a variety of situations.

[0003] Recently, two-dimensional organic-inorganic hybrid perovskites have been shown to have strong polarization sensitivity, in which the parallel layered structure composed of alternating inorganic octahedral layers and organic spacer layers endows the two-dimensional organic-inorganic hybrid perovskites with natural anisotropy. More importantly, compared with inorganic two-dimensional materials, the solution processability of two-dimensional organic-inorganic hybrid perovskites makes it easy to synthesize large crystalline materials, and their out-of-plane anisotropy can be used for polarization-sensitive light detection. Although perovskite polarization-sensitive photodetectors with dynamically tunable polarization ratios show great application potential in multifunctional polarization optoelectronics and encrypted optical communications, there is still a lack of a universal and effective method to continuously regulate the optoelectronic properties and polarization ratio of two-dimensional perovskite polarization-sensitive photodetectors. Summary of the invention

[0004] The purpose of the present invention is to provide a self-powered polarization photodetector, a preparation method thereof and a method for regulating polarization ratio thereof. The self-powered polarization photodetector is a high-performance self-powered polarization photodetector based on a two-dimensional perovskite ferroelectric film / semiconductor material heterojunction and a ferroelectric-pyroelectric optoelectronic effect. The present invention utilizes the adjustable built-in electric field characteristic of ferroelectric materials to achieve dynamic regulation of the polarization ratio.

[0005] The present invention is achieved in that:

[0006] The present invention provides a self-powered polarization photodetector based on a two-dimensional perovskite ferroelectric film / semiconductor material heterojunction. The device structure includes a conductive substrate layer, a two-dimensional perovskite ferroelectric film layer (i.e., a light absorption layer), a semiconductor material layer, and a metal top electrode layer from bottom to top, wherein the material of the two-dimensional perovskite ferroelectric film layer is (BDA) 0.7 (BA 2 ) 0.3 (EA) 2 Pb 3 Br 10 :x%Ce 3+ (x=0, 1, 3, 5, 7 or 10), (BDA) (EA) 2 Pb3 Br 10 、(BDA) 0.7 (BA 2 ) 0.3 (MA) 4 Pb 5 I 16 、(TMIM)PbI 3 or (BA 2 )(EA) 2 Pb 3 I 10 etc., BDA is 1,4-butanediamine, BA is n-butylamine, EA is ethylenediamine, MA is methylamine, and TMIM is (iodomethyl)trimethylammonium. The two-dimensional perovskite ferroelectric thin film layer and the semiconductor material layer form a heterojunction with polarization properties.

[0007] In the above scheme, preferably, the semiconductor material layer is any one of the following four materials: PC61BM, PTAA, P3HT, or a mixture of PTAA and P3HT.

[0008] In the above scheme, preferably, the self-powered polarization photodetector also includes a hole transport layer or an electron transport layer arranged between the conductive substrate layer and the two-dimensional perovskite ferroelectric thin film layer.

[0009] In the above scheme, preferably, the material of the hole transport layer is PEDOT:PSS, and the material of the electron transport layer is SnO 2 .

[0010] In the above scheme, preferably, the metal top electrode layer is Au, MoO 3 One of: / Ag or Bi / Ag.

[0011] In the above scheme, preferably, the two-dimensional perovskite ferroelectric thin film layer with low defects is prepared by heated spin coating.

[0012] The method for preparing the self-powered polarization photodetector provided by the present invention comprises the following steps:

[0013] a. Pre-treating the conductive substrate;

[0014] b. Preparation of two-dimensional perovskite ferroelectric thin film: fix the conductive substrate on a heated spin coater, heat it to 50-80°C and keep it constant, take 25-50 μL of the pre-prepared perovskite precursor solution and drop it on the conductive substrate, spin coat it at a speed of 2000-4000 rpm for 10-50 seconds, and then anneal it at 60-100°C for 5-20 minutes to obtain a two-dimensional perovskite ferroelectric thin film layer;

[0015] c. dissolving a semiconductor material in a chlorobenzene solution, and then spin coating the solution onto the two-dimensional perovskite ferroelectric film to obtain a semiconductor material layer; the semiconductor material is PC61BM, PTAA, P3HT or a mixture of PTAA and P3HT;

[0016] d. Deposit the metal top electrode layer using a thermal evaporator.

[0017] In a preferred embodiment, the thickness of the two-dimensional perovskite ferroelectric thin film layer is 250-300 nm.

[0018] In a preferred embodiment, the conductive substrate is an ITO rigid substrate.

[0019] In a preferred embodiment, the ITO rigid substrate needs to be fully immersed in a 0.4wt% PEIE aqueous solution for 1 min before preparing the sample, then washed in deionized water for 3s, and finally thermally annealed at 100°C for 10 min to improve the wettability of the conductive substrate to the perovskite film.

[0020] In a preferred embodiment, in step d, the speed of depositing the metal top electrode layer is The thickness of the metal top electrode layer is 50-150nm.

[0021] The polarization ratio of the self-powered polarization photodetector in the present invention is regulated by the following method:

[0022] (1) Apply different polarization voltages to the device;

[0023] (2) Perform polarization tests on the device and observe changes in the polarization ratio of the device.

[0024] Polarization voltages of different directions and magnitudes are applied to the device to test the saturation polarization voltage of the device to be greater than 1 min.

[0025] The present invention controls the intensity of the built-in electric field of a two-dimensional perovskite ferroelectric thin film heterojunction by applying different polarization voltages on the device, thereby achieving dynamic control of the polarization ratio of the device.

[0026] In a preferred solution, the different polarization voltages applied above need to be within the saturation polarization voltage of the device.

[0027] In a preferred solution, the polarization test on the device requires that the polarized light be incident vertically on the built-in electric field of the polarization device.

[0028] In a preferred solution, when the polarization voltage is applied to the device, the direction of applying the polarization voltage can be changed.

[0029] The present invention utilizes the adjustable built-in electric field property of two-dimensional perovskite ferroelectric materials to achieve dynamic regulation of polarization ratio on the same device. The present invention can solve the problem that the polarization ratio cannot be dynamically regulated in the prior art, and has the potential to be actually applied to polarization-sensitive photodetectors.

[0030] Compared with the prior art, the advantages of the present invention are:

[0031] 1. The two-dimensional perovskite ferroelectric thin film layer prepared by the present invention is prepared in one step by adopting a heated spin coating method, which simplifies the preparation process.

[0032] 2. The present invention uses the prepared two-dimensional perovskite ferroelectric film / semiconductor material heterojunction polarization photodetector to achieve polarization detection and polarization ratio regulation. The core is that as the polarization voltage increases, the built-in electric field (V bi ) increases, changing the device’s open circuit voltage (V oc ). The additional electric field induced by the polarization voltage can enhance or weaken the separation and transport of photoexcited electron-hole pairs. When a forward polarization voltage is applied to the device, the electric dipole film inside the perovskite ferroelectric aligns with the external electric field. This alignment enhances the built-in electric field (E bi +ΔE), resulting in an upward bending of the energy band. Therefore, this promotes the separation and transport of photogenerated carriers, suppresses the recombination of carriers, and improves the polarization ratio of the photodetector. On the contrary, when a reverse polarization voltage is applied, the electric dipoles in the perovskite ferroelectric film align with the direction of the external electric field, resulting in a decrease in the built-in electric field of the photodetector (E bi -ΔE). This phenomenon causes the energy band to bend downward, which inhibits the separation and transport of photogenerated carriers and thus reduces the polarization ratio of the photodetector. This process is conducive to the dynamic regulation of the polarization ratio in polarization photodetectors.

[0033] 3. The polarization ratio control method described in the present invention is applicable to heterojunction polarization photodetectors with different structures and different response bands. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 It is a schematic structural diagram of the self-powered polarization photodetector of the present invention.

[0035] Figure 2 The two-dimensional perovskite ferroelectric film (BDA) prepared in Example 1 of the present invention 0.7 (BA 2 ) 0.3 EA 2 Pb 3 Br 10 :5Ce 3+ SEM image of .

[0036] Figure 3 The two-dimensional perovskite ferroelectric film (BDA) prepared in Example 1 of the present invention 0.7 (BA 2 ) 0.3 EA 2 Pb 3 Br 10 :5Ce 3+ XRD pattern of .

[0037] Figure 4 The two-dimensional perovskite ferroelectric film (BDA) prepared in Example 1 of the present invention 0.7 (BA 2 ) 0.3 EA 2 Pb 3 Br 10 :5Ce 3+ and (BDA) 0.7 (BA 2 ) 0.3 EA 2 Pb 3 Br 10 Abs chart.

[0038] Figure 5 The two-dimensional perovskite ferroelectric film (BDA) in Example 1 of the present invention 0.7 (BA 2 ) 0.3 EA 2 Pb 3 Br 10 :5Ce 3 + Cross-sectional SEM image of the polarized photodetector.

[0039] Figure 6 The two-dimensional perovskite ferroelectric film (BDA) in Example 1 of the present invention 0.7 (BA 2 ) 0.3 EA 2 Pb 3 Br 10 :5Ce 3 + A graph showing the light response of a polarized photodetector as a function of polarization angle.

[0040] Figure 7 It is a polarization test diagram of the polarization photodetector in Example 1 of the present invention; wherein, (a) a diagram showing the change of the polarization device current over time under different polarization voltages, (b) a polar coordinate diagram corresponding to several representative voltages, and (c) a polarization ratio change diagram. DETAILED DESCRIPTION

[0041] The present invention proposes a self-powered polarization photodetector based on a two-dimensional perovskite ferroelectric film / semiconductor material heterojunction, a preparation method thereof, and a method for regulating polarization ratio thereof. The device preparation process is simple, and the ferroelectric film can be obtained by simple methods such as chemical synthesis. The present invention constructs a photodetector based on a two-dimensional perovskite ferroelectric film, and utilizes the adjustable built-in electric field of the ferroelectric material to regulate the polarization ratio of the polarization device.

[0042] The present invention integrates ferroelectric materials into heterostructures. On the one hand, the built-in electric field in the heterostructure can be used to adjust the change of the photocurrent at the heterojunction interface with the angle of polarized light; on the other hand, the built-in electric field at the interface of the heterostructure can separate photogenerated electron-hole pairs and reduce recombination, thereby improving the sensitivity of the self-powered polarization-sensitive photodetector. By changing the amplitude and direction of the ferroelectric polarization voltage, the built-in electric field of the heterojunction can be modulated, thereby achieving controllable polarization ratio adjustment and adjustable polarization characteristics. In addition, ferroelectrics themselves have pyroelectric properties. Due to the interaction of semiconductor properties, photon excitation and pyroelectric effects, pyroelectric optoelectronics effects show great potential in improving responsiveness, response speed and spectral range. Therefore, the present invention proposes a general strategy to electrically modulate the polarization ratio of a self-powered polarization-sensitive photodetector using the ferroelectric-pyroelectric optoelectronics effect in two-dimensional perovskites.

[0043] The embodiment of the present invention uses a Stanford SRS current preamplifier (SR570) and a Stanford SRS function generator (DS345) system to characterize the working performance characteristics of a self-powered polarization photodetector.

[0044] The self-powered polarization photodetector provided by the present invention has a structure that includes a conductive substrate layer, a two-dimensional perovskite ferroelectric thin film layer, a semiconductor material layer and a metal top electrode layer from bottom to top. Preferably, an electron transport layer or a hole transport layer (referred to as the electron or hole transport layer) can also be provided between the conductive substrate layer and the two-dimensional perovskite ferroelectric thin film layer. Figure 1 As shown, Figure 1 That is, it shows a schematic structural diagram of a self-powered polarization photodetector containing an electron or hole transport layer.

[0045] The conductive substrate layer can be any one of conductive glass (conductive layer is ITO or FTO) or silicon wafer, with a size of 1×1cm 2 -5×5cm 2 .

[0046] The two-dimensional perovskite ferroelectric thin film layer and the semiconductor material layer form a heterojunction.

[0047] The thickness of the two-dimensional perovskite ferroelectric thin film layer is 250-300nm. The two-dimensional perovskite ferroelectric thin film layer can be specifically made of the following materials: (BDA) 0.7 (BA2 ) 0.3 (EA) 2 Pb 3 Br 10 :x%Ce 3+ (x=0, 1, 3, 5, 7 or 10), (BDA) (EA) 2 Pb 3 Br 10 、(BDA) 0.7 (BA 2 ) 0.3 (MA) 4 Pb 5 I 16 :(TMIM)PbI 3 and (BA 2 )(EA) 2 Pb 3 I 10 Etc. Among them, BDA is 1,4-butanediamine, BA is n-butylamine, EA is ethylenediamine, MA is methylamine, and TMIM is (iodomethyl)trimethylammonium.

[0048] The semiconductor material layer is a mixture of PTAA and P3HT, PC61BM, PTAA or P3HT.

[0049] The metal top electrode layer is located on the semiconductor material layer, which is made of Au, MoO 3 One of Bi / Ag or Bi / Ag electrodes, with a thickness of 50-150nm.

[0050] The present invention is described in detail below through specific embodiments.

[0051] Example 1

[0052] This example prepares a bottom-up structure of ITO glass / cerium ion-doped two-dimensional perovskite ferroelectric film (BDA) 0.7 (BA 2 ) 0.3 (EA) 2 Pb 3 Br 10 :5% Ce 3+ / PTAA:P3HT / Au self-powered polarization photodetector, the preparation method is as follows:

[0053] 1) First, cut a piece of paper with a size of 1×1cm 2The ITO glass was ultrasonically cleaned in acetone, ethanol, and deionized water for 15 minutes, then dried with a dry nitrogen stream, and then treated with 80W oxygen plasma for 10 minutes. The substrate was further immersed in a 0.4wt% PEIE (polyethyleneimine) aqueous solution for 1 minute, then washed in deionized water for 3 seconds, and finally thermally annealed at 100°C for 10 minutes to improve the wettability of the substrate to the film.

[0054] 2) Prepare perovskite precursor solution: According to the solute ratio in the table below, prepare (BDA)EA with a solvent volume ratio of DMF:DMSO of 4:1 2 Pb 3 Br 10 and(BA) 2 EA 2 Pb 3 Br 10 Perovskite solution. Then the two precursor solutions are mixed according to the volume ratio (V (BDA)EA2Pb3Br10 :V (BA)2EA2Pb3Br10 =7:3) mixed preparation (BDA) 0.7 (BA 2 ) 0.3 (EA) 2 Pb 3 Br 10 Perovskite solution 10mL.

[0055]

[0056] 3) Prepare the cerium ion doping precursor solution: 10 mL of (BDA) 0.7 (BA 2 ) 0.3 (EA) 2 Pb 3 Br 10 The perovskite precursor solution was added to 48 mg of Ce(acac) 3 In the equation (BDA), we get 0.7 (BA 2 ) 0.3 (EA) 2 Pb 3 Br 10 :5% Ce 3+ Ce ion doping precursor solution.

[0057] 4) Ce-doped two-dimensional perovskite ferroelectric thin films (BDA) 0.7 (BA 2 ) 0.3 (EA) 2 Pb 3 Br 10 :5% Ce 3+Preparation: Fix the conductive substrate on a heated spin coater, heat to 70°C and keep it constant, take 25μL of cerium ion doped precursor solution and drop it on the conductive substrate, spin coat at 4000rpm for 20s; anneal at 80°C for 10min to obtain a cerium ion doped two-dimensional perovskite ferroelectric film.

[0058] According to the process of step 4), a two-dimensional perovskite ferroelectric film without cerium ion doping is prepared for subsequent comparative testing.

[0059] The SEM images, XRD patterns and Abs patterns of the obtained cerium ion-doped two-dimensional perovskite ferroelectric thin films are shown in Figure 2 , Figure 3 and Figure 4 As shown. From the SEM image, it can be seen that the surface morphology of the cerium ion-doped two-dimensional perovskite ferroelectric film is uniform and has no pinholes. From the XRD image, it can be seen that the two main diffraction peaks at 15.31° and 30.49° correspond to (BDA) 0.7 (BA 2 ) 0.3 (EA) 2 Pb 3 Br 10 The (111) and (202) crystal planes of the perovskite film indicate that the perovskite film has a good crystal orientation. From the Abs graph, it can be seen that cerium ion doping increases the absorbance of the film at 230nm-350nm.

[0060] 5) PTAA (2 mg / mL) and P3HT (1 mg / mL) were spin-coated in a chlorobenzene solution onto a low-defect, high-stability cerium ion-doped two-dimensional perovskite ferroelectric film to obtain a two-dimensional perovskite ferroelectric film / PTAA:P3HT heterojunction.

[0061] 6) Using thermal evaporator The Au electrode layer was deposited at a speed of 50 nm to obtain a polarization photodetector based on a two-dimensional perovskite ferroelectric film / PTAA:P3HT heterojunction.

[0062] The cross-sectional SEM image of the obtained polarization photodetector is shown in Figure 5 Finally, the wire and the conductive electrode were connected with silver paste and then connected to the test platform for testing. Under the irradiation of 320nm laser, the light response under zero polarization voltage changes with the polarization angle as shown in the figure Figure 6 As shown. Figure 6 It can be seen that as the polarization voltage applied to the polarization device increases, the built-in electric field (V bi ) increases, changing the device’s open circuit voltage (V oc). The additional electric field induced by the polarization voltage can enhance or weaken the separation and transport of photoexcited electron-hole pairs. When a positive polarization voltage is applied to the device (from ITO to Au), the electric dipole film inside the perovskite ferroelectric aligns with the external electric field. This alignment enhances the built-in electric field (E bi +ΔE), resulting in an upward bending of the energy band. Therefore, this promotes the separation and transport of photogenerated carriers, suppresses carrier recombination, and improves the polarization ratio of the photodetector. On the contrary, when a reverse polarization voltage is applied from Au to ITO, the electric dipoles in the perovskite ferroelectric film align with the direction of the external electric field, resulting in a decrease in the built-in electric field of the photodetector (E bi -ΔE). This phenomenon causes the energy band to bend downward, thereby inhibiting the separation and transport of photogenerated carriers, thereby reducing the polarization ratio of the photodetector. The change of polarization device current over time under different polarization voltages is shown in the figure Figure 7 (a) shows the polar coordinate diagram and polarization ratio changes of the polarization device under different polarization voltages. Figure 7 As shown in (b) and (c).

[0063] Example 2

[0064] In this example, a bottom-up structure of ITO glass / DJ phase two-dimensional perovskite ferroelectric film (BDA) (EA) is prepared. 2 Pb 3 Br 10 Polarized photodetector with / PC61BM / metal top electrode (Bi / Ag).

[0065] 1) First, cut a piece of paper with a size of 1×1cm 2 The ITO glass conductive substrate was ultrasonically cleaned in acetone, ethanol, and deionized water for 15 minutes, then dried with a dry nitrogen stream, and then treated with 80W oxygen plasma for 10 minutes. The substrate was further immersed in a 0.4wt% PEIE (polyethyleneimine) aqueous solution for 1 minute, then washed in deionized water for 3 seconds, and finally thermally annealed at 100°C for 10 minutes to improve the wettability of the substrate to the film.

[0066] 2) Prepare DJ phase perovskite precursor solution: According to the solute ratio in the table below, prepare (BDA)EA with a solvent volume ratio of DMF:DMSO of 4:1 2 Pb 3 Br 10 Perovskite solution 10mL.

[0067]

[0068] 3) DJ phase two-dimensional perovskite ferroelectric thin film (BDA) (EA) 2 Pb 3 Br10 Preparation: The conductive substrate was fixed on a heated spin coater, heated to 70°C and kept constant, 25 μL of DJ phase perovskite precursor solution was dripped onto the conductive substrate, and spin-coated at 4000 rpm for 20 seconds; annealed at 80°C for 10 minutes to obtain a DJ phase two-dimensional perovskite ferroelectric film (BDA)(EA) 2 Pb 3 Br 10 .

[0069] 4) Spin-coat PC61BM in chlorobenzene solution (20 mg / mL) onto a low-defect, high-stability DJ phase two-dimensional perovskite ferroelectric film to obtain a DJ phase two-dimensional perovskite ferroelectric film / PC61BM heterojunction.

[0070] 5) Using thermal evaporator The Bi electrode layer was deposited at a rate of 12 nm thick, and the metal top electrode Ag was deposited at a rate of The thickness of the metal top electrode Ag is 100nm, and a polarization photodetector based on DJ phase two-dimensional perovskite ferroelectric film / PC61BM heterojunction is obtained. Finally, the wire and the conductive electrode are connected with silver paste and connected to the test platform to test the change of light response with polarization angle under multiple wavelength laser irradiation and different polarization voltages, and the polarization ratio is calculated for comparison to obtain the dynamic regulation of polarization ratio in the polarization photodetector.

[0071] Example 3

[0072] The bottom-up structure prepared in this embodiment is ITO glass / PEDOT:PSS hole transport layer / perovskite ferroelectric film (BDA) 0.7 (BA 2 ) 0.3 (MA) 4 Pb 5 I 16 Polarized photodetector with / PC61BM / metal top electrode (Bi / Ag).

[0073] 1) First, cut a piece of paper with a size of 1×1cm 2 The ITO glass was ultrasonically cleaned in acetone, ethanol, and deionized water for 15 minutes, then dried with a dry nitrogen stream, and then treated with 80W oxygen plasma for 10 minutes. The substrate was further immersed in a 0.4wt% PEIE (polyethyleneimine) aqueous solution for 1 minute, then washed in deionized water for 3 seconds, and finally thermally annealed at 100°C for 10 minutes to improve the wettability of the substrate to the film.

[0074] 2) Prepare perovskite precursor solution: Prepare (BDA) 0.7 (BA 2 ) 0.3(MA) 4 Pb 5 I 16 Perovskite precursor solution: According to the solute ratio in the table below, prepare (BDA)MA with a solvent volume ratio of DMF:DMSO of 9:1 4 Pb 5 I 16 and(BA) 2 MA 4 Pb 5 I 16 Then the two perovskite solutions were mixed in a volume ratio (V (BDA)MA4Pb5I16 :V (BA)2MA4Pb5I16 =7:3) mixed preparation (BDA) 0.7 (BA 2 ) 0.3 (MA) 4 Pb 5 I 16 Perovskite solution 10mL.

[0075]

[0076] 3) Preparation of PEDOT:PSS (4083) hole transport layer: 30 μL PEDOT:PSS (4083) was added dropwise onto a conductive substrate and spin coated at 5000 rpm for 60 s; annealed at 150° C. for 30 min to obtain a PEDOT:PSS hole transport layer.

[0077] 4) Perovskite ferroelectric thin film (BDA) 0.7 (BA 2 ) 0.3 (MA) 4 Pb 5 I 16 Preparation: The conductive substrate was fixed on a heated spin coater, heated to 70°C and kept constant, 25 μL of the perovskite precursor solution was dripped onto the conductive substrate, and spin-coated at 3000 rpm for 20 seconds; annealed at 80°C for 10 minutes to obtain a two-dimensional perovskite ferroelectric film (BDA) 0.7 (BA 2 ) 0.3 (MA) 4 Pb 5 I 16 .

[0078] 5) Spin-coat PC61BM in chlorobenzene solution (20 mg / mL) onto a two-dimensional perovskite ferroelectric film with low defects and high stability to obtain a perovskite ferroelectric film / PC61BM heterojunction.

[0079] 6) Using thermal evaporator The Bi electrode layer was deposited at a rate of 12 nm thick, and the metal top electrode Ag was deposited at a rate of The thickness of the metal top electrode Ag is 100nm, and a polarization photodetector based on the perovskite ferroelectric film / PC61BM heterojunction is obtained. Finally, the wire and the conductive electrode are connected with silver paste and connected to the test platform to test the change of light response with polarization angle under laser irradiation of multiple wavelengths and different polarization voltages, and the polarization ratio is calculated and compared to obtain the dynamic regulation of the polarization ratio in the polarization photodetector.

[0080] Example 4

[0081] In this embodiment, the bottom-up structure is ITO glass / SnO 2 Electron transport layer / two-dimensional perovskite ferroelectric film (BA 2 )(EA) 2 Pb 3 I 10 / P3HT / metal top electrode (MoO 3 / Ag) self-powered polarization photodetector.

[0082] 1) First, cut a piece of paper with a size of 1×1cm 2 The ITO glass was ultrasonically cleaned in acetone, ethanol, and deionized water for 15 minutes, then dried with a dry nitrogen stream, and then treated with 80W oxygen plasma for 10 minutes. The substrate was further immersed in a 0.4wt% PEIE (polyethyleneimine) aqueous solution for 1 minute, then washed in deionized water for 3 seconds, and finally thermally annealed at 100°C for 10 minutes to improve the wettability of the substrate to the film.

[0083] 2) Configure SnO 2 Electron transport layer solution: colloidal SnO with a concentration of 15 wt% was prepared with deionized water. 2 The aqueous dispersion was diluted to 5 wt % to obtain SnO 2 Electron transport layer solution.

[0084] 3) SnO 2 Preparation of electron transport layer: Take 30 μL SnO 2 The electron transport layer solution was dropped onto the conductive substrate and spin coated at 3000 rpm for 30 s. The SnO 2 Electron transport layer.

[0085] 4) Prepare perovskite precursor solution: According to the solute ratio in the table below, the solvent DMF:DMSO:NMP volume ratio is 8:2:1 (BA) 2 (EA) 2 Pb 3 I 10Perovskite precursor solution 10mL.

[0086]

[0087] 5) Two-dimensional perovskite ferroelectric thin films (BA 2 )(EA) 2 Pb 3 I 10 Preparation: The conductive substrate was fixed on a heated spin coater, heated to 80°C and kept constant, 25 μL of the perovskite precursor solution was dripped onto the conductive substrate, and spin-coated at 4000 rpm for 20 seconds; annealed at 90°C for 20 minutes to obtain a two-dimensional perovskite ferroelectric film (BA 2 )(EA) 2 Pb 3 I 10 .

[0088] 6) Spin-coating P3HT in a chlorobenzene solution (20 mg / mL) onto a low-defect, high-stability two-dimensional perovskite ferroelectric film to obtain a two-dimensional perovskite ferroelectric film / P3HT heterojunction.

[0089] 7) Using thermal evaporator The deposition rate of MoO 3 The electrode layer has a thickness of 10 nm and the deposition rate of the metal top electrode Ag is The thickness of the metal top electrode Ag is 100nm, and a polarization photodetector based on a two-dimensional perovskite ferroelectric film / P3HT heterojunction is obtained. Finally, the wire and the conductive electrode are connected with silver paste and connected to the test platform to test the change of light response with polarization angle under laser irradiation of multiple wavelengths and different polarization voltages, and the polarization ratio is calculated for comparison to obtain the dynamic regulation of the polarization ratio in the polarization photodetector.

[0090] The above is only a preferred embodiment of the present invention. It should be noted that, for those skilled in the art, several improvements can be made without departing from the principles of the present invention, and these improvements should also be considered as the protection scope of the present invention. The structures, devices and operating methods not specifically described and explained in the present invention are implemented according to conventional means in the art unless otherwise specified and limited.

Claims

1. A self-powered polarization photodetector, characterized in that: Its structure includes a conductive substrate layer, a two-dimensional perovskite ferroelectric film layer, a semiconductor material layer and a metal top electrode layer from bottom to top; the two-dimensional perovskite ferroelectric film layer and the semiconductor material layer form a heterojunction; wherein the material of the two-dimensional perovskite ferroelectric film layer is (BDA) 0.7 (BA2) 0.3 (EA)2Pb3Br 10 :x%Ce 3+ 、(BDA)(EA)2Pb3Br 10 、(BDA) 0.7 (BA2) 0.3 (MA)4Pb5I 16 , (TMIM)PbI3 or (BA2)(EA)2Pb3I 10 , BDA is 1,4-butanediamine, BA is n-butylamine, EA is ethylenediamine, MA is methylamine, TMIM is (iodomethyl)trimethylammonium; x=0, 1, 3, 5, 7 or 10.

2. The self-powered polarization photodetector according to claim 1, characterized in that: The semiconductor material layer is PC61BM, PTAA, P3HT or a mixture of PTAA and P3HT.

3. The self-powered polarization photodetector according to claim 1, characterized in that: It also includes a hole transport layer or an electron transport layer arranged between the conductive substrate layer and the two-dimensional perovskite ferroelectric thin film layer.

4. The self-powered polarization photodetector according to claim 3, characterized in that: The material of the hole transport layer is PEDOT:PSS, and the material of the electron transport layer is SnO2.

5. The self-powered polarization photodetector according to claim 1, characterized in that: The metal top electrode layer is one of Au, MoO3 / Ag or Bi / Ag.

6. A method for preparing a self-powered polarization photodetector, characterized in that: The steps include: a. Pre-treating the conductive substrate; b. Preparation of two-dimensional perovskite ferroelectric thin film: fix the conductive substrate on a heated spin coater, heat it to 50-80°C and keep it constant, take 25-50 μL of the pre-prepared perovskite precursor solution and drop it on the conductive substrate, spin coat it at a speed of 2000-4000 rpm for 10-50 seconds, and then anneal it at 60-100°C for 5-20 minutes to obtain a two-dimensional perovskite ferroelectric thin film layer; c. dissolving the semiconductor material in a chlorobenzene solution and then spin coating it onto the two-dimensional perovskite ferroelectric film to obtain a semiconductor material layer; The semiconductor material is PC61BM, PTAA, P3HT or a mixture of PTAA and P3HT; d. Deposit the metal top electrode layer using a thermal evaporator.

7. The method for preparing the self-powered polarization photodetector according to claim 6, characterized in that: In step d, the speed of depositing the metal top electrode layer is The thickness of the metal top electrode layer is 50-150nm.

8. The self-powered polarization photodetector according to any one of claims 1 to 5 and the method for controlling the polarization ratio of the self-powered polarization photodetector prepared by the method according to claim 6 or 7, characterized in that: The steps include: (1) Applying polarization voltage to the device; (2) By changing the magnitude and / or direction of the polarization voltage, the intensity of the built-in electric field of the two-dimensional perovskite ferroelectric thin film heterojunction is regulated, thereby achieving dynamic regulation of the polarization ratio of the device.

9. The method for controlling the polarization ratio of the self-powered polarization photodetector according to claim 8, characterized in that: In step (2), polarization voltages are applied sequentially from small to large in the same direction, and polarized light hits the built-in electric field of the polarization photodetector vertically.

10. The method for controlling the polarization ratio of the self-powered polarization photodetector according to claim 8, characterized in that: In step (2), the different polarization voltages applied must be within the saturation polarization voltage of the device.

Images