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

Abstract

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

Description

Application of a self-driven perovskite photodetector in visible light sensing chips Technical Field

[0001] This invention belongs to the field of visible light detection, specifically relating to the application of a self-driven perovskite photodetector in a visible light photosensitive chip. Background Technology

[0002] Visible photodetectors are electronic devices that convert light signals in the 400-780nm wavelength range into electrical signals. They are widely used in various fields of military and civilian production and daily life, such as visible light measurement, imaging, communication, medical monitoring, and industrial automatic control. Commercial visible photodetectors are mainly based on inorganic semiconductor silicon, but silicon faces two major challenges in the field of visible light detection:

[0003] (1) Silicon has high responsivity in the infrared band, so an infrared filter is needed. However, the use of the filter will reduce light absorption, especially in the red band of visible light, which reduces the device responsivity and sensitivity.

[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, an additional power supply is required to drive it, and the manufacturing process of single crystal silicon is complex.

[0005] Therefore, the aforementioned problems or shortcomings not only increase manufacturing costs but also make it difficult to meet the development requirements of miniaturization and portability of electronic devices, resulting in limited applications. In particular, it is relatively difficult to provide long-term power in some extreme or harsh environments. Therefore, there is an urgent need to develop a visible photodetector that can operate on its own and has excellent detection performance.

[0006] Organic-inorganic hybrid lead halide perovskites can be prepared using a low-temperature solution method, which is simple and provides a direct bandgap semiconductor material. They exhibit high visible light absorption coefficients, high carrier mobility, and no infrared response, making them ideal next-generation visible light detection materials. Currently reported high-efficiency self-driven perovskite visible photodetectors achieve fast response, large linear dynamic range, and high specific detectivity, with detection performance comparable to single-crystal silicon. Unfortunately, these devices are based on the relatively unstable three-dimensional perovskite material, exhibiting poor long-term operational stability (less than 50 hours, according to Nat. Electron. 3, 156–164 (2020); Nat. Electron. 5, 511–518 (2022)), failing to meet the stable operational requirements of practical applications. Low-dimensional perovskite detectors, with their inherent high stability, exhibit significant advantages in operational stability. However, their large exciton binding energy and continuous horizontal growth parallel to the substrate direction hinder carrier diffusion and collection in the device's operating direction, resulting in visible light detection performance far inferior to three-dimensional perovskite detectors (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 for commercial detectors. Summary of the Invention

[0007] To address the limitation of applications caused by insufficient visible light detection performance of existing silicon-based and perovskite visible light detectors, this invention provides an efficient, stable, and self-driving perovskite photodetector for use in visible-band photosensitive chips, including but not limited to heart rate and pulse monitoring, container planting, automatic street light activation, automatic brightness adjustment of display panels, and visible light imaging.

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

[0009] An application of a self-driven perovskite photodetector in visible light photosensitive chips; particularly in photosensitive chips for visible light array imaging.

[0010] The aforementioned 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 street light activation, visible light photosensitive chips used in automatic brightness adjustment of display panels, visible light photosensitive chips used in distance measurement, 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 aforementioned self-driven perovskite photodetector includes electrodes, a first charge transport layer, a second charge transport layer, and a perovskite layer. The perovskite layer is a thin film with an interdigitated structure formed by low-dimensional and three-dimensional perovskites. The low-dimensional perovskite can be any one or more combinations of zero-dimensional, one-dimensional, and two-dimensional perovskites. The first charge transport layer is one or more combinations of a hole transport layer and an electron blocking layer, while the second charge transport layer is one or more combinations of an electron transport layer and a hole blocking layer; or the first charge transport layer is one or more combinations of an electron transport layer and a hole blocking layer, while the second charge transport layer is one or more combinations of an electron transport layer or a hole blocking layer. The interdigitated structure formed by the low-dimensional and three-dimensional perovskites is where the low-dimensional perovskite interweaves in an interdigitated manner within the three-dimensional perovskite.

[0012] The aforementioned interdigitated structure can be a regular or irregular polygon; the interdigitation distance is 0.001-10 μm; the interdigitation height is 0.001-2 μm; and the perovskite layer thickness is 0.01-2 μm. This interdigitated thin film structure ensures that charge carriers can be rapidly dissociated and transported through the three-dimensional perovskite component, ensuring excellent visible light detection performance. Furthermore, the highly stable interdigitated low-dimensional perovskite component present in the thin film can suppress ion migration and increase the device's operational stability. This self-driven perovskite photodetector can be used in visible light band detection applications free from power supply limitations and infrared interference.

[0013] The perovskite layer described above is prepared by the following method: spin-coating a perovskite precursor solution onto a hole transport layer; spin-coating at a speed of 1000-9000 rpm, spin-coating for 2-180 seconds, followed by annealing at 20-150°C for 1-150 minutes; preferably, spin-coating at a speed of 2000-5000 rpm, spin-coating for 20-60 seconds, followed by annealing at 80-120°C for 10-30 minutes. The perovskite precursor solution is prepared by dissolving a mixture of metal cations, halogen or pseudohalogen anions, and monovalent organic cations in a solvent. 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 or a mixture of DMF and DMSO. The preferred perovskite precursor solution is a mixture of m-fluorophenylamine 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 a mixture of m-chlorophenylamine iodine, methylamine chloride, and lead iodide in a molar ratio of 1.5-2.4:3-3.6:4; or a mixture of m-chlorophenylethylamine chloride, methylamine iodine, 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, formamidinium, fluoroanisidine, fluorophenylethylamine, chloroanisidine, chlorophenylethylamine, bromoanisidine, and bromophenylethylamine.

[0015] Preferably, the 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 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'-tetracycline...

[0018] [N,N-Di(4-methoxyphenyl)amino]-9,9'-spirodifluorene, tin oxide, titanium oxide, C60 derivatives (PC) 61 One or a combination of BM, C60, and BCP.

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

[0020] The fabrication method of the above-mentioned self-driven perovskite photodetector includes the following steps:

[0021] 1) Fabrication of transparent electrodes: 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-coat the first charge transport layer solution onto the treated substrate at a speed of 3000-6000 rpm for 30-60 seconds, and then anneal at 100-150℃ for 10-30 minutes.

[0023] 3) Preparation of the perovskite layer: A perovskite precursor solution is spin-coated onto the first charge transport layer, wherein the perovskite precursor solution is prepared by dissolving a mixture of metal cations, halogen or pseudohalogen anions and monovalent organic cations in a solvent, with the mass concentration of the solute in the solution being 15-50%; the solvent is any one or a combination of N,N-dimethylformamide, dimethyl sulfoxide, and N-methylpyrrolidone.

[0024] 4) Preparation of the second charge transport layer: Spin-coating or vapor-depositing the second charge transport layer on the perovskite layer; preferably, vapor-depositing 40-65 nm of C60 followed by vapor-depositing 5-40 nm of BCP, or directly spin-coating PC. 61 BM solution;

[0025] 5) Fabrication of metal electrodes: Metal is deposited on the second charge transport layer by vapor deposition.

[0026] Or it may include the following steps:

[0027] 1) Fabrication of transparent electrodes: 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-coat the second charge transport layer on the treated substrate at a speed of 3000-5000 rpm for 30-60 seconds, anneal at 100-150℃ for 20-60 minutes, and immediately proceed with the preparation of the next layer.

[0029] 3) Preparation of the perovskite layer: A perovskite precursor solution is spin-coated onto the second charge transport layer, wherein the perovskite precursor solution is prepared by dissolving a mixture of metal cations, halogen or pseudohalogen anions and monovalent organic cations in a solvent, with the mass concentration of the solute in the solution being 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-coat the first charge transport layer solution onto the perovskite layer at a speed of 3000-5000 rpm for 30-60 seconds;

[0031] 5) Fabrication of metal electrodes: Metal is deposited on the first charge transport layer by vapor deposition.

[0032] Preferably, the first charge transport layer is PTAA, 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 needs to be included in the examples).

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

[0035] The advantages of this invention compared with the prior art are as follows:

[0036] In this invention, the interdigitated perovskite layer is a special thin film structure formed by the self-assembly of a perovskite precursor solution, in which a low-dimensional perovskite component with interdigitated ...

[0037] In the application of this invention, the three-dimensional perovskite component in the thin film structure ensures the material's high mobility, large absorption coefficient, and suitable band gap, enabling the device to have 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 device's dark current, and effectively enhances the device's operational stability.

[0038] The self-driven perovskite photodetector provided by this invention has both high-efficiency visible light detection performance and operational stability. It can be processed by solution method, and the fabrication process is simple. It does not require infrared filters and power supplies, which greatly reduces the device manufacturing cost, device size and weight, and can be easily integrated with other electronic devices.

[0039] This invention solves the problems of complex manufacturing processes, the need for external power supplies and infrared filters, and the poor operational stability of high-efficiency perovskite visible light detectors, which limit their application. Attached Figure Description

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

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

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

[0043] Figure 4 is a comparison of the responsivity of the perovskite photodetector of Embodiment 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 is a comparison of the working stability of the perovskite photodetector of Embodiment 1 provided by the present invention and the commercial high-performance silicon-based visible light detector (Hamamatsu S1087, Japan) with a self-driven detection working frequency of 0.5Hz white light source.

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

[0046] Figure 7 shows the application of the self-driven perovskite photodetector of Embodiment 1 to automatic brightness adjustment of a mobile phone display screen.

[0047] Figure 8 shows the change of electrical signal generated by the self-driven perovskite photodetector of Example 1 as it is applied to the photosensitive chip of a mobile phone display screen, and the change with ambient light intensity.

[0048] Figure 9 is a diagram of the imaging test system in the photosensitive chip for visible light imaging using the self-driven perovskite detector in Example 1.

[0049] Figure 10 shows the imaging test results of the self-driven perovskite detector in Example 1 applied to the photosensitive chip for visible light imaging.

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

[0051] Figure 12 shows the absorption spectrum of the perovskite layer in Example 2 provided by the present invention;

[0052] Figure 13 is a schematic diagram comparing the specific detectivity, response speed, dark current, and linear dynamic range performance of the self-driven perovskite photodetector of Embodiment 2 provided by the present invention with those of different types of commercially available visible light detectors.

[0053] Figure 14 shows the application of the self-driven perovskite photodetector of Embodiment 2 provided by the present invention in the intelligent switch and dimming system of solar street lights;

[0054] Figure 15 is a transient response speed time diagram of the self-driven perovskite photodetector of Embodiment 2 provided by the present invention.

[0055] Figure 16 shows the evolution of photocurrent output by the self-driven interdigitated perovskite photodetector and the three-dimensional perovskite (MAPbI3) in Embodiment 2 of the present invention when simulating the detection of the highest illuminance of sunlight during the use of streetlights (left figure); and the working lifetime figure of the photocurrent change curve fitting of the self-driven interdigitated perovskite photodetector (right figure).

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

[0057] Figure 18 shows the response spectrum of the self-driven interdigitated perovskite photodetector in Example 3.

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

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

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

[0061] Figure 22 shows the response spectrum of the self-driven interdigitated perovskite photodetector in Example 4;

[0062] Figure 23 is a graph showing the change of photocurrent signal over time in the self-driven interdigitated perovskite photodetector used for monitoring the highest illuminance of sunlight in intelligent greenhouse planting in Example 4.

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

[0064] Figure 25 shows the response spectrum of the self-driven interdigitated perovskite photodetector in Example 5;

[0065] Figure 26 is a diagram showing the minimum green light response illuminance of the self-driven interdigitated perovskite photodetector in Example 5.

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

[0067] Figure 28 is a schematic diagram of the self-driven perovskite photodetector provided by the present invention connected to a controller and applied to a visible light detection scenario. Detailed Implementation

[0068] The present invention will be described in detail below with reference to specific embodiments.

[0069] Example 1

[0070] The self-driven perovskite photodetector is fabricated 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) onto the treated substrate at a spin speed of 5000 rpm for 30 seconds, followed by annealing at 100°C for 10 minutes.

[0073] 3) Preparation of the perovskite layer: After preheating the substrate to 100℃, 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 onto the first charge transport layer at a spin speed of 5000 rpm. After spin-coating for 20 seconds, the substrate was annealed at 80-100℃ for 10 minutes.

[0074] 4) Fabrication of the electron transport layer (i.e., the second charge transport layer): The electron transport layer is fabricated on the perovskite layer under a vacuum of 10... -7 During the Torr process, C60 with a wavelength of 60 nm was deposited (the evaporation rate was 0.1 A / s for the first 3 nm, and then the rate increased uniformly to 1 A / s), followed by the deposition of BCP with a wavelength of 15 nm (the evaporation rate was 0.1 A / s for the first 3 nm, and then the rate increased uniformly to 1 A / s).

[0075] 5) Fabrication of metal electrodes: On the electron transport layer at a vacuum level of 10... -7 During the Torr process, Cu with a wavelength of 100 nm was deposited by evaporation (the evaporation rate was 0.3 A / s for the first 3 nm, and then the rate increased uniformly to 1 A / s).

[0076] Figure 1 shows the cross-sectional electron microscope image of the perovskite layer in this embodiment, which reveals the interdigitated morphological structure.

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

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

[0079] Figure 3 shows a comparison of the noise current of the perovskite photodetector and the commercially available high-performance silicon-based visible light detector (Hamamatsu S1087, Japan) in this embodiment. At 1 Hz, the noise current of the perovskite detector is significantly lower than that of the silicon-based detector. Therefore, it can be reasonably inferred that perovskite will have a lower noise floor than silicon when operating under self-driven DC conditions.

[0080] Figure 4 shows a comparison of the responsivity of the perovskite photodetector and the commercially available high-performance silicon-based visible light detector (Hamamatsu S1087, Japan) under self-driven operation in this embodiment. The responsivity of the perovskite device is higher than that of the silicon detector across the entire visible light band, and the EQE efficiency at each wavelength is closer to the ideal efficiency of 100%. Furthermore, the addition of an infrared filter to the silicon-based detector leads to a significant reduction in the device's responsivity to red light.

[0081] Figure 5 shows a comparison of the working stability of the perovskite photodetector and the high-performance silicon-based visible light detector (Hamamatsu S1087, Japan) with a self-driven on / off time interval of 10 seconds. After 90 hours of continuous operation, the dark current of the perovskite device remains almost unchanged, while the dark current of the silicon detector increases significantly after 60 hours, demonstrating the excellent working stability of the perovskite device.

[0082] In this embodiment, a self-driven perovskite photodetector and a high-performance silicon-based visible light detector (Hamamatsu S1087, Japan) were applied to underwater laser ranging. Figure 6 shows a comparison of the ranging errors under different laser intensities. This experiment simulates the attenuation of underwater laser intensity with increasing distance using laser intensity. The results show that the self-driven perovskite photodetector can still achieve relatively accurate ranging even in low-light conditions.

[0083] The self-driven perovskite photodetector in this embodiment is directly connected to the light source controller of the mobile phone display panel without the need for bias voltage. It is applied in an automatic brightness adjustment system for mobile phone displays, as shown in Figure 7. The self-driven perovskite photodetector can effectively generate photocurrents of varying magnitudes in real time in response to changes in ambient light intensity, thereby sending electrical signals to the panel controller to adjust the light intensity, as shown in Figure 8. Such a self-driven photosensitive chip is not only more energy-efficient, but also reduces the size of traditional photosensitive chips by eliminating the need for a driving power supply and filters, potentially further reducing the thickness of the display panel.

[0084] The self-driven perovskite photodetector and thin-film transistor of this embodiment are integrated for visible light imaging. The imaging results are transmitted to a mobile terminal in real time via WiFi. The visible light imaging test system is shown in Figure 9. The 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, displaying the corresponding image in 256 grayscale levels. The real-time test imaging results are shown in Figure 10. The real-time displayed imaging results are consistent with the mask pattern, indicating that the perovskite visible light detector imaging array system of this embodiment can clearly and in real time image the mask pattern, possessing good real-time imaging capabilities.

[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 fabricated 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-coat PEDOT:PSS solution (model 4083) on the treated substrate at a speed of 3000-5000 rpm for 45 seconds, and then anneal at 120-150℃ for 30 minutes.

[0090] 3) Preparation of perovskite layer: A perovskite precursor solution (m-chlorobenzylamine iodine, methylamine chloride, and lead iodide in a molar ratio of 1.6:3.2:4, 35% by mass dissolved in DMF solvent) was spin-coated onto the hole transport layer at a speed of 5000 rpm. After spin-coating for 20 seconds, the solution was annealed at 90°C for 10 minutes.

[0091] 4) Preparation of the electron transport layer (i.e., the second charge transport layer): PC at a concentration of 20 mg / ml was spin-coated onto the perovskite layer. 61 BM solution, solvent is chlorobenzene, rotation speed is 1000 rpm, coating time is 60 seconds;

[0092] 5) Fabrication of metal electrodes: On the electron transport layer at a vacuum level of 10... -7 During the Torr process, 3 nm of Cr was deposited (evaporation rate 0.1 A / s), followed by 100 nm of Cu (evaporation rate of 0.2 A / s for the first 3 nm, then the rate increased uniformly to 1 A / s).

[0093] Figure 11 shows the cross-sectional electron microscope image of the perovskite layer in this embodiment, revealing an interdigitated morphological structure. In this embodiment, the interdigitation distance is 0.001-2 μm, the interdigitation height is 0.01-0.4 μm, and the perovskite layer thickness is approximately 0.54 μm.

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

[0095] Figure 11 shows a performance comparison between the self-driven perovskite photodetector and commonly used commercially available typical visible light detectors, including silicon photodiodes (Hamamatsu S1087), avalanche diodes (Sorebo APD130A2), and femtowatt detectors (Sorebo PDF10A2). The comprehensive comparison shows that the self-driven perovskite photodetector in this embodiment has parameter performance that is closer to the equilateral triangle of an ideal detector in terms of specific detectivity, 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 on-time and brightness adjustment system of solar streetlights. As shown in Figure 14, the self-driven perovskite detector is directly connected to the controller. By detecting the ambient light intensity, it sends different electrical signals to the controller, thereby controlling the on-time and intensity adjustment of the solar streetlights. The transient response speed of the self-driven perovskite detector is shown in Figure 15. The rise and fall times are both less than 20 ns, indicating that the electrical signal can change rapidly in real time according to the ambient light intensity, thereby intelligently controlling the on-time and brightness of the solar streetlights.

[0097] The left side of Figure 16 shows the photocurrent evolution of the self-driven interdigitated perovskite photodetector and the ordinary three-dimensional perovskite MAPbI3 in this embodiment when simulating the detection of the highest illuminance during street lamp use. After continuous testing for over 1300 hours, the photocurrent of the interdigitated perovskite device did not decrease relative to its initial value, while the photocurrent of the three-dimensional perovskite MAPbI3 decreased by more than 30% after 50 hours. This data indicates that three-dimensional perovskite is difficult to meet the stability requirements of detectors in practical applications, while the stability of the interdigitated perovskite device is significantly improved compared to the three-dimensional perovskite. The right side of Figure 16 shows the fitting of the photocurrent variation curve of the interdigitated perovskite photodetector to its working lifetime. The results show that the Ttime of the interdigitated perovskite device during continuous operation... 50 Life expectancy is predicted to be 51,606 hours, which is approximately 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 stable visible light detection.

[0099] Example 3

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

[0101] 1) Substrate treatment: The clean ITO conductive glass substrate is treated with oxygen plasma on the surface and then the next layer is prepared immediately.

[0102] 2) Preparation of hole transport layer (i.e. first charge transport layer): spin-coat 2PACz solution (MeO-2PACz with a doping ratio not exceeding 1 / 3 of 2PACz) onto the treated substrate at a speed of 4000 rpm for 45 seconds, and then anneal at 100℃ for 10 minutes.

[0103] 3) Preparation of perovskite layer: A perovskite precursor solution (m-chlorophenylethylamine chloride, methylamine iodine, lead iodide molar ratio of 2:3:4, 25% mass concentration dissolved in a mixed solvent of DMF and DMSO, wherein the proportion of DMSO does not exceed 1 / 10 of the total solvent volume) was spin-coated onto the hole transport layer. After preheating the substrate at 90°C for 5 minutes, spin-coating was performed at a speed of 4500 rpm. After spin-coating for 40 seconds, the substrate was annealed at 100°C for 20 minutes.

[0104] 4) Fabrication of the electron transport layer (i.e., the second charge transport layer): The electron transport layer is fabricated on the perovskite layer under a vacuum of 10... -7 Fabrication of a 45 nm C60 electrode (evaporation rate of 0.2 A / s for the first 3 nm, then a uniform rate increase to 1 A / s) was performed using a Torr method, followed by the deposition of a 30 nm BCP electrode (evaporation rate of 0.2 A / s for the first 3 nm, then a uniform rate increase to 1 A / s). The electrode was fabricated on an electron transport layer under a vacuum of 10... -7 During the Torr process, 8 nm of Cr was deposited (evaporation rate 0.1 A / s), followed by 100 nm of Au (evaporation rate of 0.2 A / s for the first 3 nm, then the rate increased uniformly to 1 A / s).

[0105] Figure 17 shows the cross-sectional electron microscope image of the perovskite layer in this embodiment, which exhibits an interdigitated morphological structure. In this embodiment, the interdigitation distance is approximately 0.001-0.9 μm, the interdigitation height is 0.005-0.5 μm, and the perovskite layer thickness is approximately 0.5 μm.

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

[0107] Figure 19 shows an experimental photograph of the self-driven interdigitated perovskite photodetector used for underwater optical communication in this embodiment.

[0108] In this embodiment, the data diagram of the self-driven interdigitated perovskite photodetector used for transmitting binary signals in underwater optical communication is shown in Figure 20. The self-driven interdigitated perovskite photodetector 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 stable visible light detection.

[0110] Example 4

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

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

[0113] 2) Preparation of electron transport layer (i.e., second charge transport layer): SnO2 solution (tin oxide: pure water = 1:3) was spin-coated onto the treated substrate at a speed of 4000 rpm for 30 seconds. After spin-coating, the substrate was annealed at 150℃ for 30 minutes and cooled to room temperature. Then, potassium chloride aqueous solution (concentration of 10 mM) was spin-coated at a speed of 2000 rpm for 30 seconds and annealed at 110℃ for 10 minutes.

[0114] 3) Preparation of the perovskite layer: A perovskite precursor solution (m-fluorobenzylamine chloride, methylamine iodine, lead iodide, and lead chloride in a molar ratio of 2:3:0.1, 38% by mass, dissolved in a mixed solvent of DMF and NMP, wherein the proportion of NMP does not exceed 1 / 10 of the total solvent volume, spin-coating at 4500 rpm for 40 seconds, followed by annealing at 85°C for 120 minutes;

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

[0116] 5) Fabrication of the metal electrode: On the first charge transport layer, under a vacuum of 10... -7 Au is deposited at a density of 100 nm during Torr (evaporation rate 0.2-2 A / s).

[0117] Figure 21 shows the cross-sectional electron microscope image of the perovskite layer in this embodiment, which exhibits an interdigitated morphological structure. In this embodiment, the interdigitation distance is approximately 0.001-0.08 μm, the interdigitation height is 0.02-0.55 μm, and the perovskite layer thickness is approximately 0.65 μm.

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

[0119] In this embodiment, the unencapsulated self-driven interdigitated perovskite photodetector is used to monitor simulated sunlight intensity in smart greenhouse cultivation. Under the maximum simulated sunlight intensity AM1.5G, the magnitude of the device's output electrical signal changes over time as shown in Figure 23. The results show that after continuously detecting the maximum illuminance for 2400 hours, the device's output photocurrent signal only decreases by about 12%, indicating that the self-driven interdigitated perovskite photodetector can achieve long-term stable application in smart greenhouse cultivation.

[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 fabricated 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): Titanium oxide solution (titanium tetrachloride: pure water = 9-10: 400) was spin-coated onto the treated substrate at a speed of 4000 rpm for 30 seconds, and then annealed at 150℃ for 30 minutes.

[0125] 3) Preparation of the perovskite layer: A perovskite precursor solution (m-fluorophenylethylamine chloride, formamidinium iodide, and lead iodide in a molar ratio of 2:3:4, 45% by mass, dissolved in a mixed solvent of DMSO and NMP, wherein the proportion of NMP does not exceed 1 / 10 of the total solvent volume, spin-coated at 4500 rpm for 40 seconds, and then annealed at 150°C for 10 minutes;

[0126] 4) Preparation of hole transport layer (i.e. first charge transport layer): spin-coat 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), 10 μl cobalt salt (300 mg / ml acetonitrile)) onto the perovskite layer.

[0127] 5) Fabrication of the metal electrode: On the first charge transport layer, under a vacuum of 10... -7 During the Torr process, 100 nm of Ag was deposited by evaporation (the evaporation rate was 0.1 A / s for the first 3 nm, and then the rate increased uniformly to 1 A / s).

[0128] The electron microscope image of the cross-sectional morphology of the perovskite layer in this embodiment is shown in Figure 24, which reveals an interdigitated morphological structure. In this embodiment, the interdigitation distance is approximately 0.001-0.3 μm, the interdigitation height is 0.1-1 μm, and the perovskite layer thickness is approximately 1.2 μm.

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

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

[0131] In this embodiment, a self-driven interdigitated perovskite photodetector is combined with a green LED for heart rate / pulse monitoring. The data results are shown in Figure 27. The results show a typical heart rate waveform, which is converted 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 photosensitive chip to achieve sensitive heart rate and pulse monitoring.

[0133] The above description is only a preferred embodiment of the present invention. Those skilled in the art can make various modifications and variations based on the present invention. Any similar improvements, substitutions, modifications, etc., made within the principles of the present invention should be included within the scope of protection of the claims of the present invention.

Claims

1. An application of a self-driven perovskite photodetector in a visible light photosensitive chip; the self-driven perovskite photodetector includes electrodes, a first charge transport layer, a second charge transport layer, and a perovskite layer; wherein, The perovskite layer is a thin film with an interdigitated structure formed by low-dimensional perovskite and three-dimensional perovskite. The interdigitated structure is a regular or irregular polygon with a spacing of 0.001-10 μm, a height of 0.001-2 μm, and a thickness of 0.01-2 μm.

2. The application according to claim 1, characterized in that... The visible light photosensitive chip mentioned is a visible light photosensitive chip used in heart rate and pulse monitoring, a visible light photosensitive chip used in container planting, a visible light photosensitive chip used in automatic street light activation, a visible light photosensitive chip used in automatic brightness adjustment of display panels, a visible light photosensitive chip used in distance measurement, or a visible light photosensitive chip used in visible light array imaging.

3. The application according to claim 1, characterized in that... The first and second charge transport layers are made from one or more of the following raw materials: 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'-tetra[N,N-di(4-methoxyphenyl)amino]-9,9'-spirodifluorene, tin oxide, titanium oxide, C60 derivatives, C70 derivatives, C60, copper bath, and doped 2,3,5,6-tetrafluoro-7,7',8,8'-tetracyanodimethyl-p-benzoquinone.

4. The application according to claim 1, characterized in that... The perovskite layer is prepared by the following method: spin-coating a perovskite precursor solution onto a charge transport layer; the spin-coating speed is 1000-9000 rpm, and after spin-coating for 2-180 seconds, annealing is performed at 20-150℃ for 1-150 minutes; wherein, the perovskite precursor solution is a mixture of metal cations, halogen or pseudohalogen anions and monovalent organic cations dissolved in a solvent, and the mass concentration of the solute in the solution is 15-45%; the solvent is any one or a combination of N,N-dimethylformamide, dimethyl sulfoxide, and N-methylpyrrolidone.

5. The application according to claim 4, characterized in that... The metal cations are one or more combinations of lead, rubidium, cesium, potassium, and sodium; the halogen or pseudohalogen anions include one or more combinations of fluorine, chlorine, bromine, iodine, and thiocyanate; and the monovalent organic cations include one or more combinations of methylamine, formamidinium, fluoroanisidine, fluorophenylethylamine, chloroanisidine, chlorophenylethylamine, bromoanisidine, and bromophenylethylamine.

6. The application according to claim 1, characterized in that... The photodetector, from top to bottom, consists of 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.

7. The application according to claim 6, characterized in that... The transparent electrode comprises indium tin oxide or fluorine-doped tin oxide; the metal electrode is any one or a combination of gold, copper, chromium, and silver.

8. The application according to claim 1, characterized in that... The fabrication of the self-driven perovskite photodetector includes the following steps: 1) Fabrication of the transparent electrode: a clean indium tin oxide or fluorine-doped tin oxide glass substrate is subjected to surface oxygen plasma treatment; 2) Fabrication of the first charge transport layer: a first charge transport layer solution is spin-coated onto the treated substrate at a rotation speed of 3000-6000 rpm for 30-60 seconds, followed by annealing at 100-150℃ for 10-30 minutes; 3) Fabrication of the perovskite layer: a perovskite precursor solution is spin-coated onto the first charge transport layer. The perovskite precursor solution is prepared by dissolving a mixture of metal cations, halogen or pseudohalogen anions, and monovalent organic cations in a solvent, with the solute having a mass concentration of 15-50% in the solution; 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 vapor-depositing the second charge transport layer onto the perovskite layer; 5) Preparation of the metal electrode: vapor-depositing metal onto the second charge transport layer; or coating... The process includes the following steps: 1) Preparation of the transparent electrode: A clean indium tin oxide (ITO) or fluorine-doped tin oxide (FDO) glass substrate is subjected to surface oxygen plasma treatment; 2) Preparation of the second charge transport layer: The second charge transport layer is spin-coated onto the treated substrate at a rotation speed of 3000-5000 rpm for 30-60 seconds, followed by annealing at 100-150°C for 20-60 minutes; 3) Preparation of the perovskite layer: A perovskite precursor solution is spin-coated onto the second charge transport layer, wherein the perovskite precursor solution is composed of metal cations. A mixture of halogen or pseudohalogen anions and monovalent organic cations is 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 onto the perovskite layer at a speed of 3000-5000 rpm for 30-60 seconds; 5) Preparation of the metal electrode: vapor-depositing metal onto the first charge transport layer.

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