Application of self-driven perovskite photoelectric detector in visible light sensing chip

Abstract

The invention discloses an application of a self-driven perovskite photoelectric detector in a visible light sensitive chip. The self-driven perovskite photoelectric detector comprises an electrode, a first charge transport layer, a second charge transport layer and a perovskite layer, wherein the perovskite layer is a thin film of an interdigital structure formed by low-dimensional and three-dimensional perovskite, and the low-dimensional perovskite is any one or a combination of more of zero-dimensional perovskite, one-dimensional perovskite and two-dimensional perovskite; the first charge transport layer is one or a combination of a hole transport layer and an electron blocking layer, and the second charge transport layer is one or a combination of an electron transport layer and a hole blocking layer; or the first charge transport layer is one or a combination of more of the electron transport layer and the hole blocking layer, and the second charge transport layer is one or a combination of more of the electron transport layer and the hole blocking layer. According to the perovskite photoelectric detector, the problem of limited application caused by insufficient visible light detection performance of the existing silicon-based and perovskite visible light detectors is solved.

Description

Technical Field

[0001] The present invention belongs to the field of visible light detection, and in particular relates to the application of a self-driven perovskite photoelectric detection in a visible light photosensor chip. Background Art

[0002] Visible photodetectors are electronic devices that convert optical signals in the 400-780nm band into electrical signals. They are widely used in various fields of military and national production and life, such as visible light measurement, imaging, communications, medical monitoring, industrial automatic control, etc. Commercial visible photodetectors are mainly based on inorganic semiconductor silicon, but silicon has the following two main problems in the field of visible light detection:

[0003] (1) Silicon has a high responsivity in the infrared band, and an infrared filter needs to be added. However, the use of the filter will reduce light absorption, especially the red light band in the visible light, which reduces the responsivity and sensitivity of the device;

[0004] (2) Silicon is an indirect bandgap semiconductor material with a low absorption coefficient in the visible light band. In order to improve the visible light detection performance of the device, it needs to be equipped with an additional power supply to drive it, and the manufacturing process of single crystal silicon is complicated;

[0005] Therefore, the above-mentioned problems or shortcomings not only increase the manufacturing cost, but also make it difficult to meet the development requirements of miniaturization and portability of electronic devices, resulting in limited applications, especially in some extreme or harsh environments where long-term power supply is relatively difficult. Therefore, there is an urgent need to develop a visible photodetector that can be self-driven and has excellent detection performance.

[0006] Organic-inorganic hybrid lead halide perovskite can be prepared by low-temperature solution method with simple process. It is a direct bandgap semiconductor material with large visible light absorption coefficient, high carrier mobility and no infrared response. It is regarded as an ideal new generation of visible light detection material. The efficient self-driven perovskite visible photodetectors reported in the literature can achieve fast response, large linear dynamic range and high specific detection rate, and the detection performance is comparable to that of single crystal silicon. Unfortunately, these devices are based on three-dimensional perovskite materials with poor stability and poor long-term working stability, less than 50 hours (Nat. Electron. 3, 156–164 (2020); Nat. Electron. 5, 511–518 (2022).), which cannot meet the requirements of stable working in practical applications. Low-dimensional perovskite detectors with natural high stability show great advantages in terms of working stability, but due to their large exciton binding energy and the horizontal continuous growth parallel to the substrate direction, which hinders the diffusion and collection of carriers in the working direction of the device, the device's visible light detection performance is far inferior to that of three-dimensional perovskites (NanoEnergy 57, 761–770 (2019)). In summary, the reported self-driven perovskite visible photodetectors cannot simultaneously meet the requirements of high performance and stable operation of commercial detectors. Summary of the invention

[0007] In order to solve the problem that the existing silicon-based and perovskite visible light detectors are limited in application due to insufficient visible light detection performance, the present invention provides an efficient, stable and self-driven perovskite photodetector for use in visible band photosensitive chips, including but not limited to heart rate and pulse monitoring, container planting, automatic turning on of street lights, automatic adjustment of display panel brightness, and visible light imaging.

[0008] The technical solution of the present invention is as follows:

[0009] A self-driven perovskite photodetector is used in a visible light photosensitive chip, in particular in a photosensitive chip for visible light array imaging.

[0010] The above-mentioned visible light photosensitive chips include but are not limited to visible light photosensitive chips used in heart rate and pulse monitoring, visible light photosensitive chips used in container planting, visible light photosensitive chips used in automatic turning on of street lights, visible light photosensitive chips used in automatic adjustment of display panel brightness, visible light photosensitive chips used in ranging, visible light photosensitive chips used in visible light array imaging, photosensitive chips used in X-ray array imaging, and photosensitive chips used in gamma-ray array imaging.

[0011] The self-driven perovskite photodetector comprises an electrode, a first charge transport layer, a second charge transport layer and a perovskite layer; wherein the perovskite layer is a thin film of an interdigitated structure formed by low-dimensional and three-dimensional perovskites, and the low-dimensional perovskite is any one or more combinations of zero-dimensional, one-dimensional and two-dimensional; the first charge transport layer is one or more combinations of hole transport layer and electron blocking layer, and the second charge transport layer is one or more combinations of electron transport layer and hole blocking layer; or the first charge transport layer is one or more combinations of electron transport layer and hole blocking layer, and the second charge transport layer is one or more combinations of electron transport layer or hole blocking layer. The interdigitated structure formed by the low-dimensional and three-dimensional perovskites is that the low-dimensional perovskite is interspersed in the three-dimensional perovskite in an interdigitated shape.

[0012] The interdigitated structure can be a regular or irregular polygon; the interdigitated spacing is 0.001-10μm; the interdigitated height is 0.001-2μm; and the thickness of the perovskite layer is 0.01-2μm. The interdigitated film structure ensures that carriers can be dissociated and transmitted at high speed through the three-dimensional perovskite component, ensuring excellent visible light detection performance, and the high-stability interdigitated low-dimensional perovskite component in the film can inhibit ion migration and increase the working stability of the device. The self-driven perovskite photodetector can be exempted from the visible light band detection application with limited power supply environment and infrared interference.

[0013] The above-mentioned perovskite layer is prepared by the following method: spin coating a perovskite precursor solution on the hole transport layer; the spin coating speed is 1000-9000 rpm, after spin coating for 2-180 seconds, annealing at 20-150°C for 1-150 minutes; preferably, the spin coating speed is 2000-5000 rpm, after spin coating for 20-60 seconds, annealing at 80-120°C for 10-30 minutes. The perovskite precursor solution is a mixture of metal cations, halogen or pseudohalogen anions and monovalent organic cations dissolved in a solvent as a solute. The mass concentration of the solute in the solution is 15-45%, preferably 20%-35%; the solvent is any one or more combinations of N,N-dimethylformamide (DMF), dimethyl sulfoxide (DMSO), and N-methylpyrrolidone (NMP), preferably DMF, a mixed solvent of DMF and DMSO. Preferably, the perovskite precursor solution is a mixture of m-fluorobenzylamine iodine, methylamine chloride, lead iodide, and rubidium iodide in a molar ratio of 2-2.4:3-3.8:4:0.01-0.5; or the perovskite precursor solution is a mixture of m-chlorobenzylamine iodine, methylamine chloride, and lead iodide in a molar ratio of 1.5-2.4:3-3.6:4; or the perovskite precursor solution is a mixture of m-chlorobenzylamine chloride, methylamine iodide, and lead iodide in a molar ratio of 1.5-2.3:2.8-3.2:4.

[0014] Preferably, the metal cation is one or a combination of lead, rubidium, cesium, potassium, and sodium; the halogen or pseudohalogen anion includes one or a combination of fluorine, chlorine, bromine, iodine, and thiocyanate; and the monovalent organic cation includes one or a combination of methylamine, formamidine, fluorobenzylamine, fluorophenethylamine, chlorobenzylamine, chlorophenethylamine, bromobenzylamine, and bromophenethylamine.

[0015] Preferably, the above-mentioned photodetector comprises, from top to bottom, a transparent electrode, a first charge transport layer, an interdigitated perovskite layer, a second charge transport layer and a metal electrode, or comprises, from top to bottom, a transparent electrode, a second charge transport layer, an interdigitated perovskite layer, a first charge transport layer and a metal electrode.

[0016] Preferably, the transparent electrode comprises indium tin oxide (ITO) or fluorine-doped tin oxide (FTO).

[0017] Preferably, the charge transport layer comprises poly 3,4-ethylenedioxythiophene / polystyrene sulfonate (PEDOT:PSS), poly [bis (4-phenyl) (2,4,6-trimethylphenyl) amine] (PTAA), [2- (3,6-dimethoxy-9H-carbazole-9-yl) ethyl] phosphonic acid (MeO-2PACz), [2- (9H-carbazole-9-yl) ethyl] phosphonic acid (2PACz), 2,2',7,7'-tetrakis

[0018] [N,N-di(4-methoxyphenyl)amino]-9,9'-spirobifluorene, tin oxide, titanium oxide, carbon 60 derivative (PC 61 BM), carbon 60 (C60), bathocuproine (BCP) or a combination of several thereof.

[0019] Preferably, the metal electrode is any one or a combination of gold (Au), copper (Cu), chromium (Cr), and silver (Ag), preferably one or two of gold, copper, and chromium.

[0020] The method for preparing the self-driven perovskite photodetector comprises the following steps:

[0021] 1) Preparation of transparent electrode: a clean indium tin oxide or fluorine-doped tin oxide glass substrate is subjected to surface oxygen plasma treatment;

[0022] 2) Preparation of the first charge transport layer: spin coating the first charge transport layer solution on the treated substrate at a rotation speed of 3000-6000 rpm for 30-60 seconds, followed by annealing at 100-150° C. for 10-30 minutes;

[0023] 3) Preparation of the perovskite layer: spin coating a perovskite precursor solution on the first charge transport layer, wherein the perovskite precursor solution is a mixture of metal cations, halogen or pseudohalogen anions and monovalent organic cations dissolved in a solvent as a solute, and the mass concentration of the solute in the solution is 15-50%; the solvent is any one or more combinations of N,N-dimethylformamide, dimethyl sulfoxide, and N-methylpyrrolidone;

[0024] 4) Preparation of the second charge transport layer: Spin coating or evaporation of the second charge transport layer on the perovskite layer; preferably, evaporation of 40-65nm C60, then evaporation of 5-40nm BCP or direct spin coating of PC 61 BM solution;

[0025] 5) Preparation of metal electrode: Evaporating metal on the second charge transport layer.

[0026] Or include the following steps:

[0027] 1) Preparation of transparent electrode: a clean indium tin oxide or fluorine-doped tin oxide glass substrate is subjected to surface oxygen plasma treatment;

[0028] 2) Preparation of the second charge transport layer: Spin coating the second charge transport layer on the treated substrate at a speed of 3000-5000 rpm for 30-60 seconds, annealing at 100-150° C. for 20-60 minutes, and then immediately preparing the next layer;

[0029] 3) Preparation of the perovskite layer: spin coating a perovskite precursor solution on the second charge transport layer, wherein the perovskite precursor solution is a mixture of metal cations, halogen or pseudohalogen anions and monovalent organic cations dissolved in a solvent as a solute, and the mass concentration of the solute in the solution is 15-50%; the solvent is any one or more combinations of N,N-dimethylformamide, dimethyl sulfoxide, and N-methylpyrrolidone;

[0030] 4) Preparation of the first charge transport layer: spin coating the first charge transport layer solution on the perovskite layer at a rotation speed of 3000-5000 rpm for 30-60 seconds;

[0031] 5) Preparation of metal electrode: Evaporating metal on the first charge transport layer.

[0032] Preferably, the first charge transport layer is made of PTAA or 2PACz or PEDOT:PSS.

[0033] Preferably, the second charge transport layer is made of C60 / BCP or PC 61 BM or SnO2 (the application of SnO2 is required in the embodiment.

[0034] The application scenarios of the visible light sensing chip of the above-mentioned self-driven perovskite photodetector include but are not limited to harsh environmental areas with limited power supply environment, unmanned scenes and underwater, and mobile electronic devices; the application fields include but are not limited to visible light measurement, communication, imaging, and automatic control systems.

[0035] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0036] In the application of the present invention, the interdigitated perovskite layer is formed by self-assembly of a perovskite precursor solution to form a special thin film structure with an interdigitated low-dimensional perovskite component inserted into a three-dimensional perovskite component, which solves the problem that the conventional low-dimensional perovskite has difficulty in carrier diffusion and collection due to horizontal growth or the mobility of the vertically grown low-dimensional perovskite is still lower than that of the three-dimensional perovskite.

[0037] In the application of the present invention, the three-dimensional perovskite component in the thin film structure ensures the high mobility, large absorption coefficient and suitable band gap of the material, so that the device has high absorbance and fast response in the visible light band and no infrared response. At the same time, the low-dimensional perovskite component inhibits ion migration, reduces the dark current of the device, and effectively enhances the working stability of the device.

[0038] The self-driven perovskite photodetector provided by the present invention has both high-efficiency visible light detection performance and working stability, and can be processed by solution method. The preparation process is simple and does not require infrared filters and power supplies, which greatly reduces the device manufacturing cost and device volume and weight, and can be conveniently integrated with other electronic devices for further application.

[0039] The present invention solves the problems of complex manufacturing process of current high-efficiency silicon-based visible light detectors, the need for external power supplies and infrared filters, and the application limitations caused by poor working stability of high-efficiency perovskite visible light detectors. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] Figure 1 This is an electron microscope image of the cross-sectional morphology of the interdigitated perovskite film in Example 1 provided by the present invention;

[0041] Figure 2 is the absorption spectrum of the perovskite layer of Example 1 provided by the present invention;

[0042] Figure 3 It is a comparison diagram of the noise current of the perovskite photodetector of Example 1 provided by the present invention and a commercial high-performance silicon-based visible light detector (Hamamatsu S1087, Japan);

[0043] Figure 4 This is a comparison chart of the responsivity of the perovskite photodetector of Example 1 provided by the present invention and a commercial high-performance silicon-based visible light detector (Hamamatsu S1087, Japan) under self-driven operation;

[0044] Figure 5 This is a comparison chart of the working stability of the perovskite photodetector of Example 1 provided by the present invention and a commercial high-performance silicon-based visible light detector (Japan Hamamatsu S1087) for self-driven detection of a white light source with a working frequency of 0.5 Hz;

[0045] Figure 6 The self-driven perovskite photodetector of Example 1 and the high-performance silicon-based visible light detector (Hamamatsu S1087, Japan) provided are applied to underwater visible light ranging, and the error comparison of ranging results under different light intensities is provided;

[0046] Figure 7 The self-driven perovskite photodetector of the provided embodiment 1 is applied to automatically adjust the brightness of a mobile phone display screen;

[0047] Figure 8 The self-driven perovskite photodetector of Example 1 is applied to a mobile phone display screen photosensitive chip, and a graph showing the change of the electrical signal generated by the device with the ambient light intensity;

[0048] Fig. 9 This is a diagram of an imaging test system in which the self-driven perovskite detector in Example 1 is applied to a photosensitive chip for visible light imaging;

[0049] Fig.10 This is a graph showing the imaging test results of the self-driven perovskite detector in Example 1 applied to a photosensitive chip for visible light imaging;

[0050] Fig.11 is an electron microscope image of the cross-sectional morphology of the perovskite layer of Example 2 provided by the present invention;

[0051] Fig.12 is the absorption spectrum of the perovskite layer of Example 2 provided by the present invention;

[0052] Fig.13 It is a schematic diagram comparing the detection rate, response speed, dark current and linear dynamic range performance of the self-driven perovskite photodetector of Example 2 provided by the present invention and different types of commercial visible light detectors;

[0053] Fig.14 The self-driven perovskite photoelectric detector of Example 2 provided by the present invention is applied to the intelligent switch and dimming system of solar street lamps;

[0054] Fig.15 This is a time diagram of the transient response speed of the self-driven perovskite photodetector according to Example 2 provided by the present invention;

[0055] Fig.16The following is a diagram showing the evolution of the photocurrent output by the self-driven interdigitated perovskite photodetector and the three-dimensional perovskite (MAPbI3) in Example 2 of the present invention when simulating the detection of the highest sunlight illumination during the use of a street lamp (left figure); a working life diagram of the fitting of the photocurrent variation curve of the self-driven interdigitated perovskite photodetector (right figure);

[0056] Fig.17 is an electron microscope image of the cross-sectional morphology of the perovskite layer in Example 3;

[0057] Fig.18 This is the response spectrum of the self-driven interdigitated perovskite photodetector in Example 3.

[0058] Fig.19 This is an experimental photo of the self-driven interdigitated perovskite photodetector used for underwater optical communication in Example 3.

[0059] Fig. 20 This is a data graph of the self-driven interdigitated perovskite photodetector in Example 3 used to transmit binary signals in underwater optical communication.

[0060] Fig.21 is an electron microscope image of the cross-sectional morphology of the perovskite layer in Example 4;

[0061] Fig. 22 is the response spectrum of the self-driven interdigitated perovskite photodetector in Example 4;

[0062] Fig.23 This is a graph showing the change of the photocurrent signal over time when the self-driven interdigitated perovskite photodetector in Example 4 is used for intelligent greenhouse planting monitoring and simulating the maximum sunlight illumination;

[0063] Fig.24 is an electron microscope image of the cross-sectional morphology of the perovskite layer in Example 5;

[0064] Fig.25 is the response spectrum of the self-driven interdigitated perovskite photodetector in Example 5;

[0065] Fig.26 is the lowest green light response illumination diagram of the self-driven interdigitated perovskite photodetector in Example 5;

[0066] Fig. 27 This is a data diagram of the self-driven interdigitated perovskite photodetector used for green light heart rate and pulse monitoring in Example 5;

[0067] Fig.28 Schematic diagram of the self-driven perovskite photodetector provided by the present invention being connected to a controller and applied to a visible light detection scenario. DETAILED DESCRIPTION

[0068] The present invention is described in detail below in conjunction with specific embodiments.

[0069] Example 1

[0070] The self-driven perovskite photodetector is prepared as follows:

[0071] 1) Substrate treatment: The clean ITO conductive glass substrate is subjected to surface oxygen plasma treatment;

[0072] 2) Preparation of hole transport layer (i.e., first charge transport layer): Spin-coat a PTAA solution layer (2-10 mg / ml dissolved in chlorobenzene solvent, doped with 2,3,5,6-tetrafluoro-7,7',8,8'-tetracyanodimethyl-p-benzoquinone (F4-TCNQ), doping concentration of 0.4 mg / ml) on the treated substrate at a speed of 5000 rpm, spin-coat for 30 seconds, and anneal at 100° C. for 10 minutes;

[0073] 3) Preparation of perovskite layer: After preheating the substrate at 100°C, a perovskite precursor solution (methylamine chloride, lead iodide, m-fluorobenzylamine iodide, rubidium iodide) with a molar ratio of 2.2:3.5:4:0.03, 30% mass concentration dissolved in DMF solvent) was spin-coated on the first charge transport layer at a speed of 5000 rpm. After spin coating for 20 seconds, annealing was performed at 80-100°C for 10 minutes.

[0074] 4) Preparation of electron transport layer (i.e., second charge transport layer): On the perovskite layer, a vacuum of 10 -7 Torr, evaporate 60nm of C60 (evaporation rate is 0.1A / s for the first 3nm, then the rate increases to 1A / s uniformly), and then evaporate 15nm of BCP (evaporation rate is 0.1A / s for the first 3nm, then the rate increases to 1A / s uniformly);

[0075] 5) Preparation of metal electrodes: On the electron transport layer, at a vacuum degree of 10 -7 100nm of Cu was evaporated at 2000 Torr (the evaporation rate was 0.3A / s for the first 3nm, and then increased to 1A / s at a uniform rate).

[0076] The electron microscope image of the cross-sectional morphology of the perovskite layer in this embodiment is shown in Figure 1 , showing an interdigitated morphology.

[0077] In this embodiment, the interdigital spacing is 0.001-0.2 μm; the interdigital height is 0.1-0.25 μm; and the thickness of the entire perovskite layer is 0.4 μm.

[0078] The absorption spectrum of the perovskite layer in this embodiment is shown in Figure 2 , absorption cutoff is 780nm, no infrared band response.

[0079] The comparison of the noise current of the perovskite photodetector in this embodiment and the commercial high-performance silicon-based visible light detector (Japan Hamamatsu S1087) is shown in Figure 3 At 1 Hz, the noise current of the perovskite detector is significantly lower than that of the silicon-based detector. It can be reasonably inferred that when working in self-driven DC, perovskite will have a lower background noise than silicon.

[0080] The comparison of the responsivity of the perovskite photodetector in this embodiment and the commercial high-performance silicon-based visible light detector (Hamamatsu S1087, Japan) under self-driven operation is shown in Figure 4 , the responsivity of perovskite devices is higher than that of silicon detectors in the entire visible light band, and the EQE efficiency at each wavelength is closer to the ideal efficiency of 100%. In addition, since the silicon-based detector has an infrared filter, the responsivity of the device to red light is greatly reduced.

[0081] In this embodiment, the working stability comparison of the perovskite photodetector and the high-performance silicon-based visible light detector (Japan Hamamatsu S1087) self-driven detection on / off time interval 10s light source is shown in the figure. Figure 5 After 90 hours of continuous operation, the light and dark current of the perovskite device remained almost unchanged, while the dark current of the silicon detector increased significantly after 60 hours, showing the excellent working stability of the perovskite device.

[0082] In this embodiment, the self-driven perovskite photodetector and the high-performance silicon-based visible light detector (Japan Hamamatsu S1087) are applied to underwater laser ranging. The error comparison diagram of ranging results under different laser intensities is shown in Figure 6 The experiment used laser intensity to simulate the attenuation of underwater laser intensity with increasing distance. The results showed that the self-driven perovskite photodetector can still achieve relatively accurate ranging applications in weak light.

[0083] The self-driven perovskite photodetector in this embodiment is directly connected to the light source controller of the mobile phone display panel without applying bias voltage, and is applied in the automatic brightness adjustment system of the mobile phone display screen, such as Figure 7 As shown. The self-driven perovskite photodetector can generate photocurrents of different sizes in real time in response to changes in ambient light intensity, thereby sending an electrical signal to the panel controller to adjust the light intensity, such as Figure 8 Such a self-driven photosensitive chip is not only more power-saving, but also does not require a driving power supply and a filter, which can reduce the size of the traditional photosensitive chip and is expected to further reduce the thickness of the display panel.

[0084] The self-driven perovskite photodetector and thin film transistor in this embodiment are integrated and applied to visible light imaging, and the imaging results are transmitted to the mobile terminal in real time via WiFi. The visible light imaging test system is as follows: Fig. 9The current at each point of the imaging array is obtained through the data reading system, and the data is transmitted to the mobile terminal via WiFi, and the corresponding imaging is displayed in the form of 256 grayscale. The real-time test imaging results are shown in Fig.10 As shown, the real-time displayed imaging result is consistent with the mask pattern, indicating that the perovskite visible light detector imaging array system in this embodiment can clearly and in real time image the mask pattern and has good real-time imaging capability.

[0085] The comparison of the above detection performance shows that the self-driven perovskite detector in this embodiment can achieve efficient and stable visible light detection.

[0086] Example 2

[0087] The self-driven perovskite photodetector is prepared as follows:

[0088] 1) Substrate treatment: The clean ITO conductive glass substrate is subjected to surface oxygen plasma treatment;

[0089] 2) Preparation of hole transport layer (i.e., first charge transport layer): Spin coating PEDOT:PSS solution (model 4083) on the treated substrate at a speed of 3000-5000 rpm for 45 seconds, followed by annealing at 120-150° C. for 30 minutes;

[0090] 3) Preparation of perovskite layer: spin-coat the hole transport layer with a perovskite precursor solution (m-chlorobenzylamine iodide, methylamine chloride, lead iodide in a molar ratio of 1.6:3.2:4, 35% mass concentration dissolved in DMF solvent) at a speed of 5000 rpm for 20 seconds, and then anneal at 90°C for 10 minutes;

[0091] 4) Preparation of electron transport layer (i.e., second charge transport layer): Spin-coat 20 mg / ml PC on the perovskite layer. 61 BM solution, the solvent is chlorobenzene, the rotation speed is 1000 rpm, and the coating time is 60 seconds;

[0092] 5) Preparation of metal electrodes: On the electron transport layer, at a vacuum degree of 10 -7 At 400 Torr, 3 nm of Cr was evaporated (evaporation rate 0.1 A / s), and then 100 nm of Cu was evaporated (evaporation rate for the first 3 nm was 0.2 A / s, and then the rate increased uniformly to 1 A / s).

[0093] The electron microscope image of the cross-sectional morphology of the perovskite layer in this embodiment is shown in Fig.11 , showing a finger-shaped structure. In this embodiment, the finger spacing is 0.001-2 μm, the finger height is 0.01-0.4 μm, and the thickness of the perovskite layer is about 0.54 μm

[0094] The absorption spectrum of the perovskite layer in this embodiment is shown in Fig.12 , absorption cutoff is 780nm, no infrared band response.

[0095] The performance comparison of the self-driven perovskite photodetector in Example 2 and the commonly used commercial typical visible light detector silicon photodiode (Hamamatsu S1087), avalanche diode (Solebo APD130A2), and femtowatt detector (Solebo PDF10A2) is shown in FIG. Fig.11 As shown, a comprehensive comparison shows that the parameter performance of the self-driven perovskite photodetector in this embodiment is closer to the equilateral triangle of the ideal detector in terms of specific detection rate, response speed, dark current and linear dynamic range of device operation.

[0096] The self-driven perovskite photodetector in this embodiment is applied to the automatic start-up and brightness adjustment system of solar street lamps, such as Fig.14 As shown in the figure, the self-driven perovskite detector is directly connected to the controller. By detecting the intensity of the ambient light, different electrical signals are sent to the controller to control the switch and intensity regulation of the solar street light. The transient response speed of the self-driven perovskite detector is as follows: Fig.15 As shown, the rise and fall times are both less than 20ns, indicating that the electrical signal can change quickly in real time according to the ambient light intensity, thereby intelligently controlling the opening and light intensity of the solar street light.

[0097] Fig.16 The middle left figure is a graph showing the evolution of the photocurrent output by the self-driven interdigitated perovskite photodetector in this embodiment and the ordinary three-dimensional perovskite MAPbI3 when simulating the detection of the highest sunlight illumination during the use of street lamps. After continuous testing for more than 1300 hours, the photocurrent of the interdigitated perovskite device has not decayed relative to the initial value, while the photocurrent decay of the three-dimensional perovskite MAPbI3 has exceeded 30% after 50 hours. This data shows that three-dimensional perovskites are difficult to meet the requirements for detector stability in practical applications, while the stability of interdigitated perovskite devices is significantly improved compared to three-dimensional perovskites. Fig.16 The right figure is the fitting of the working life of the interdigitated perovskite photodetector photocurrent change curve. The results show that the T 50 The life span is predicted to be up to 51,606 hours, which is approximately equal to 6 years.

[0098] The above results indicate that the self-driven interdigitated perovskite detector in this embodiment can be used as a visible light photosensitive chip to achieve long-term and stable visible light detection.

[0099] Example 3

[0100] The self-driven perovskite photodetector is prepared as follows:

[0101] 1) Substrate treatment: After the clean ITO conductive glass substrate is treated with surface oxygen plasma, the next layer is prepared immediately;

[0102] 2) Preparation of the hole transport layer (i.e., the first charge transport layer): spin coating a 2PACz solution (MeO-2PACz with a doping ratio not exceeding 1 / 3 of 2PACz) on the treated substrate at a speed of 4000 rpm for 45 seconds, followed by annealing at 100° C. for 10 minutes;

[0103] 3) Preparation of perovskite layer: spin coating the hole transport layer with a perovskite precursor solution (m-chlorophenylethylamine chloride, methylamine iodine, lead iodide in a molar ratio of 2:3:4, 25% mass concentration dissolved in a mixed solvent of DMF and DMSO, wherein the DMSO accounts for no more than 1 / 10 of the total solvent volume), preheat the substrate at 90°C for 5 minutes and then spin coating at a speed of 4500 rpm. After spin coating for 40 seconds, anneal at 100°C for 20 minutes;

[0104] 4) Preparation of electron transport layer (i.e., second charge transport layer): On the perovskite layer, a vacuum of 10 -7 Torr, 45nm of C60 was evaporated (the evaporation rate was 0.2A / s for the first 3nm, and then the rate was increased to 1A / s at a constant rate), and then 30nm of BCP was evaporated (the evaporation rate was 0.2A / s for the first 3nm, and then the rate was increased to 1A / s at a constant rate). Preparation of metal electrodes: On the electron transport layer, the vacuum degree was 10 -7 At 400 Torr, 8 nm of Cr was evaporated (evaporation rate 0.1 A / s), and then 100 nm of Au was evaporated (the evaporation rate for the first 3 nm was 0.2 A / s, and then the rate increased uniformly to 1 A / s).

[0105] The electron microscope image of the cross-sectional morphology of the perovskite layer in this embodiment is shown in Fig.17 , showing a finger-like morphology structure. In this embodiment, the finger spacing is about 0.001-0.9 μm, the finger height is 0.005-0.5 μm, and the thickness of the perovskite layer is about 0.5 μm.

[0106] The response spectrum of the self-driven interdigitated perovskite photodetector in this embodiment is shown in Fig.18 The device has no response in the infrared band, and the highest response in the visible light band can reach 0.46A / W.

[0107] The experimental photos of the self-driven interdigitated perovskite photodetector used for underwater optical communication in this embodiment are shown in Fig.19 .

[0108] The data diagram of the self-driven interdigitated perovskite photodetector used for transmitting binary signals in underwater optical communication in this embodiment is shown in Fig. 20, self-driven interdigitated perovskite photodetectors can achieve accurate real-time signal transmission.

[0109] The above results indicate that the self-driven interdigitated perovskite detector in this embodiment can be used as a visible light photosensitive chip to achieve long-term and stable visible light detection.

[0110] Example 4

[0111] The self-driven perovskite photodetector is prepared as follows:

[0112] 1) Substrate treatment: The clean FTO conductive glass substrate is subjected to surface oxygen plasma treatment;

[0113] 2) Preparation of the electron transport layer (i.e., the second charge transport layer): Spin-coat a SnO2 solution (tin oxide: pure water = 1:3) on the treated substrate at a speed of 4000 rpm for 30 seconds, anneal at 150°C for 30 minutes, cool to room temperature, spin-coat a potassium chloride aqueous solution (concentration of 10 mM), spin-coat at a speed of 2000 rpm for 30 seconds, and anneal at 110°C for 10 minutes;

[0114] 3) Preparation of perovskite layer: spin coating the perovskite precursor solution (m-fluorobenzylamine chloride, methylamine iodine, lead iodide, lead chloride in a molar ratio of 2:3:0.1, 38% mass concentration dissolved in a mixed solvent of DMF and NMP, wherein the NMP accounted for no more than 1 / 10 of the total solvent volume) on the second charge transport layer, rotating at 4500 rpm, spin coating for 40 seconds, and annealing at 85°C for 120 minutes;

[0115] 4) Preparation of hole transport layer (i.e., first charge transport layer): spin coating the perovskite layer with Spiro-OMeTAD solution (72.3 mg / ml chlorobenzene, doped with 29 μl tetra-tert-butylpyridine, 17.8 μl lithium salt (520 mg / ml acetonitrile), and 10 μl cobalt salt (300 mg / ml acetonitrile);

[0116] 5) Preparation of metal electrodes: On the first charge transport layer, a vacuum of 10 -7 100nm of Au was evaporated at 4000 Torr (evaporation rate 0.2-2A / s).

[0117] The electron microscope image of the cross-sectional morphology of the perovskite layer in this embodiment is shown in Fig.21 , showing an interdigitated structure. In this embodiment, the interdigitated spacing is about 0.001-0.08 μm, the interdigitated height is 0.02-0.55 μm, and the thickness of the perovskite layer is about 0.65 μm.

[0118] The response spectrum of the self-driven interdigitated perovskite photodetector in this embodiment is shown in Fig. 22The device has no response in the infrared band, and the maximum response in the visible light band can reach 0.47A / W.

[0119] In this embodiment, the unpackaged self-driven interdigitated perovskite photodetector is used to monitor the intensity of simulated sunlight in smart greenhouse planting. Under the maximum simulated sunlight intensity AM1.5G, the size of the device output electrical signal changes with time. Fig.23 The results showed that after 2400 hours of continuous detection of maximum illumination, the device output photocurrent signal only decayed by about 12%, indicating that the self-driven interdigitated perovskite photodetector can be stably applied in smart greenhouse cultivation applications in the long term.

[0120] The above results indicate that the self-driven interdigitated perovskite detector in this embodiment can be used as a visible light photosensitive chip to achieve stable visible light detection.

[0121] Example 5

[0122] The self-driven perovskite photodetector is prepared as follows:

[0123] 1) Substrate treatment: The clean FTO conductive glass substrate is subjected to surface oxygen plasma treatment;

[0124] 2) Preparation of electron transport layer (i.e., second charge transport layer): spin-coat titanium oxide solution (titanium tetrachloride: pure water = 9-10:400) on the treated substrate at a speed of 4000 rpm for 30 seconds, followed by annealing at 150° C. for 30 minutes;

[0125] 3) Preparation of perovskite layer: spin-coat the perovskite precursor solution (m-fluorophenylethylamine chloride, formamidine iodine, lead iodide in a molar ratio of 2:3:4, 45% mass concentration dissolved in a mixed solvent of DMSO and NMP, wherein the NMP accounts for no more than 1 / 10 of the total solvent volume) on the second charge transport layer, at a rotation speed of 4500 rpm, spin-coat for 40 seconds, and anneal at 150°C for 10 minutes;

[0126] 4) Preparation of the hole transport layer (i.e., the first charge transport layer): spin coating the perovskite layer with a PTAA solution (60 mg / ml chlorobenzene, which may be doped with 29 μl tetra-tert-butylpyridine, 17.8 μl lithium salt (520 mg / ml acetonitrile), and 10 μl cobalt salt (300 mg / ml acetonitrile);

[0127] 5) Preparation of metal electrodes: On the first charge transport layer, the vacuum degree is 10 -7 100nm of Ag was evaporated at 4000 Torr (the evaporation rate was 0.1A / s for the first 3nm, and then increased to 1A / s at a uniform rate).

[0128] The electron microscope image of the cross-sectional morphology of the perovskite layer in this embodiment is shown in Fig.24, showing an interdigitated structure. In this embodiment, the interdigitated spacing is about 0.001-0.3 μm, the interdigitated height is 0.1-1 μm, and the thickness of the perovskite layer is about 1.2 μm.

[0129] The response spectrum of the self-driven interdigitated perovskite photodetector in this embodiment is shown in Fig.25 The device has no response in the infrared band, and the highest response in the visible light band can reach 0.44A / W.

[0130] The minimum detectable green light intensity of the self-driven interdigitated perovskite photodetector in this embodiment is shown in Fig.26 , the results show that the interdigitated perovskite photodetector has extremely high sensitivity in the green light band.

[0131] The self-driven interdigitated perovskite photodetector in this embodiment is combined with a green LED for heart rate / pulse monitoring. The data results are shown in Fig. 27 The results show a typical heart rate waveform, which converts to a heart rate / pulse of approximately 96 beats per second.

[0132] The above results indicate that the self-driven interdigitated perovskite detector in this embodiment can be used as a visible light photosensor chip to realize sensitive heart rate and pulse monitoring.

[0133] The above description is only a preferred embodiment of the present invention. Technical researchers in this field can make various changes and modifications based on the present invention. Any improvements, replacements, modifications, etc. made within the principles of the present invention should be included in the scope of protection of the claims of the present invention.

Claims

1. Application of a self-driven perovskite photodetector in a visible light sensing chip.

2. The use according to claim 1, Features The visible light photosensitive chip includes but is not limited to visible light photosensitive chips used in heart rate and pulse monitoring, visible light photosensitive chips used in container planting, visible light photosensitive chips used in automatic turning on of street lights, visible light photosensitive chips used in automatic adjustment of display panel brightness, visible light photosensitive chips used in ranging, visible light photosensitive chips used in visible light array imaging, photosensitive chips used in X-ray array imaging, and photosensitive chips used in gamma-ray array imaging.

3. The use according to claim 1, Features The self-driven perovskite photodetector comprises an electrode, a first charge transport layer, a second charge transport layer and a perovskite layer; wherein the perovskite layer is a thin film of an interdigitated structure formed by low-dimensional and three-dimensional perovskites, and the low-dimensional perovskite is any one or more combinations of zero-dimensional, one-dimensional and two-dimensional; the first charge transport layer is one or more combinations of hole transport layer and electron blocking layer, and the second charge transport layer is one or more combinations of electron transport layer and hole blocking layer; or the first charge transport layer is one or more combinations of electron transport layer and hole blocking layer, and the second charge transport layer is one or more combinations of electron transport layer or hole blocking layer.

4. The use according to claim 1, Features The interdigitated shape is a regular or irregular polygon, the interdigitated distance is 0.001-10 μm, the interdigitated height is 0.001-2 μm, and the thickness of the perovskite layer is 0.01-2 μm.

5. The use according to claim 1, Features The raw materials used in the first charge transport layer and the second charge transport layer are one or a combination of poly (3,4-ethylenedioxythiophene) / polystyrene sulfonate, poly (bis (4-phenyl) (2,4,6-trimethylphenyl) amine), [2- (3,6-dimethoxy-9H-carbazole-9-yl) ethyl] phosphonic acid, [2- (9H-carbazole-9-yl) ethyl] phosphonic acid, 2,2',7,7'-tetrakis [N,N-di (4-methoxyphenyl) amino] -9,9'-spirobifluorene, tin oxide, titanium oxide, carbon 60 derivatives, carbon 70 derivatives, carbon 60, bathocuproin, and doped 2,3,5,6-tetrafluoro-7,7',8,8'-tetracyanodimethyl-p-benzoquinone.

6. The use according to claim 1, Features The perovskite layer is prepared by the following method: spin coating a perovskite precursor solution on a charge transport layer; the spin coating speed is 1000-9000 rpm, after spin coating for 2-180 seconds, annealing at 20-150°C for 1-150 minutes; wherein the perovskite precursor solution is a mixture of metal cations, halogen or pseudohalogen anions and monovalent organic cations as solutes dissolved in a solvent, and the mass concentration of the solute in the solution is 15-45%; the solvent is any one or more combinations of N,N-dimethylformamide, dimethyl sulfoxide, and N-methylpyrrolidone.

7. The use according to claim 6, Features The metal cation is one or a combination of lead, rubidium, cesium, potassium, and sodium; the halogen or pseudohalogen anion includes one or a combination of fluorine, chlorine, bromine, iodine, and thiocyanate; and the monovalent organic cation includes one or a combination of methylamine, formamidine, fluorobenzylamine, fluorophenethylamine, chlorobenzylamine, chlorophenethylamine, bromobenzylamine, and bromophenethylamine.

8. The use according to claim 1, Features The photoelectric detectors are: A transparent electrode, a first charge transport layer, an interdigitated perovskite layer, a second charge transport layer and a metal electrode, or from top to bottom, a transparent electrode, a second charge transport layer, an interdigitated perovskite layer, a first charge transport layer and a metal electrode.

9. The use according to claim 8, Features The transparent electrode comprises indium tin oxide or fluorine Doped tin oxide; the metal electrode is any one of gold, copper, chromium, and silver or a combination of several thereof.

10. The use according to claim 8, Features The preparation of the self-driven perovskite photodetector comprises the following steps: 1) Preparation of transparent electrode: a clean indium tin oxide or fluorine-doped tin oxide glass substrate is subjected to surface oxygen plasma treatment; 2) Preparation of the first charge transport layer: spin coating the first charge transport layer solution on the treated substrate at a rotation speed of 3000-6000 rpm for 30-60 seconds, followed by annealing at 100-150° C. for 10-30 minutes; 3) Preparation of the perovskite layer: spin coating a perovskite precursor solution on the first charge transport layer, wherein the perovskite precursor solution is a mixture of metal cations, halogen or pseudohalogen anions and monovalent organic cations dissolved in a solvent as a solute, and the mass concentration of the solute in the solution is 15-50%; the solvent is any one or more combinations of N,N-dimethylformamide, dimethyl sulfoxide, and N-methylpyrrolidone; 4) Preparation of the second charge transport layer: spin coating or evaporating the second charge transport layer on the perovskite layer; 5) Preparation of metal electrode: Evaporating metal on the second charge transport layer. Or include the following steps: 1) Preparation of transparent electrode: a clean indium tin oxide or fluorine-doped tin oxide glass substrate is subjected to surface oxygen plasma treatment; 2) Preparation of the second charge transport layer: spin coating the second charge transport layer on the treated substrate at a speed of 3000-5000 rpm for 30-60 seconds, and annealing at 100-150° C. for 20-60 minutes; 3) Preparation of the perovskite layer: spin coating a perovskite precursor solution on the second charge transport layer, wherein the perovskite precursor solution is a mixture of metal cations, halogen or pseudohalogen anions and monovalent organic cations dissolved in a solvent as a solute, and the mass concentration of the solute in the solution is 15-50%; the solvent is any one or more combinations of N,N-dimethylformamide, dimethyl sulfoxide, and N-methylpyrrolidone; 4) Preparation of the first charge transport layer: spin coating the first charge transport layer solution on the perovskite layer at a rotation speed of 3000-5000 rpm for 30-60 seconds; 5) Preparation of metal electrode: Evaporating metal on the first charge transport layer.

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