Photoelectric angle measuring instrument based on planar perovskite single crystal

Abstract

The present invention discloses a photoelectric angle measuring instrument based on a planar perovskite single crystal. The perovskite single crystal is used as a photosensitive substrate. Part of the single crystal surface is doped, resulting in both doped and undoped regions. A first electrode is disposed in the doped region, and a second electrode is disposed in the undoped region. The doped region between the two electrodes serves as the illumination region. When the incident angle of the light source changes, the ratio of the device's photocurrent at the first wavelength to the second wavelength changes linearly. Thus, the incident angle of the light source is obtained based on the ratio of the photocurrent at the first wavelength to the second wavelength. The angle measuring instrument of the present invention has the characteristics of low production cost, simple structure, small size, and portability.

Description

Technical Field

[0001] The present invention relates to the field of photoelectric detectors, and in particular to a photoelectric angle measuring instrument based on a planar perovskite single crystal. Background Art

[0002] Angle detection plays a vital role in many engineering applications and scientific research. For example, in civil engineering, angle detection can help measure the tilt of buildings to ensure their safety and stability. In medical equipment, angle detection can help doctors more accurately locate and diagnose conditions. Furthermore, angle detection plays an indispensable role in aerospace, robotics, automotive, and other fields.

[0003] Traditional angle detection methods primarily utilize optical methods, imaging systems, or angle detectors. Optical methods primarily utilize light interference and diffraction to achieve angle detection. While these methods offer very high measurement accuracy and resolution, their equipment is typically complex and expensive, requiring precise environmental control and sophisticated data processing. Imaging systems capture an image of an object and use image processing and analysis to determine its orientation or angle. However, this method requires complex image processing and analysis algorithms and places certain demands on camera quality and ambient lighting conditions. Angle sensors, on the other hand, convert an object's rotational motion into electrical signals, which are then analyzed to determine the object's rotation angle or orientation. While sensors offer advantages such as high accuracy, high resolution, and versatility in angle measurement, high-precision sensors also come with high costs and complex installation.

[0004] Compared to traditional angle measurement systems like optical methods and angle sensors, photodetectors offer advantages such as small size, low cost, and ease of integration, giving them great potential for angle measurement. Currently, photodetectors are used for angle detection in two main ways: one, by acting as a key component in an angle measurement system, measures changes in light intensity or direction, such as by integrating the photodetector with a light source. The other involves linking electrical parameters such as the photocurrent or voltage of the photodetector to the angle of the incident light, establishing a functional relationship between the device's electrical parameters and the incident light angle. The device's rotation angle can then be determined by measuring these parameters. Although angle measurement technology has achieved significant progress, many challenges remain. For example, some angle measurement systems are complex to design, require precise calculations, and are susceptible to environmental factors. Some high-precision angle measurement equipment is expensive and bulky, making it unsuitable for use in space-constrained environments. Therefore, it is crucial to develop angle measurement systems that are low-cost, simple in structure, compact, portable, and adaptable to diverse detection environments. Summary of the Invention

[0005] In order to avoid the shortcomings of the above-mentioned existing technologies, the present invention provides a photoelectric angle measuring instrument based on a planar perovskite single crystal, which aims to realize the sensitive change of the device's spectral response to the illumination angle through a simple process, and realize angle measurement by utilizing the relationship between the device's photocurrent ratio and the illumination angle, thereby obtaining a simple, small and portable angle detector.

[0006] The present invention solves the technical problem by adopting the following technical solutions:

[0007] A photoelectric angle measuring instrument based on a planar perovskite single crystal is characterized by using a perovskite single crystal as a photosensitive substrate. Part of the single crystal surface is doped, resulting in both doped and undoped regions. A first electrode is disposed in the doped region, and a second electrode is disposed in the undoped region, with the second electrode not contacting the doped region. The doped region between the two electrodes serves as the illumination region. As the incident angle of the light source changes, the ratio of the device's photocurrent at the first wavelength to the second wavelength changes linearly. Thus, the incident angle of the light source is determined based on this ratio of the photocurrent at the first wavelength to the second wavelength.

[0008] Furthermore, the angle measuring instrument of the present invention can use most perovskite single crystals as substrates, such as MAPbBr3, MAPbI3, MAPbCl3, etc.

[0009] Furthermore, the perovskite single crystal of the present invention can be synthesized by a temperature gradient method, an anti-solvent vapor assisted crystallization process or an inversion temperature crystallization method.

[0010] Furthermore, the doping of the present invention is accomplished by epitaxially growing a single crystal in a perovskite precursor solution containing a doping element. The doping element in the perovskite precursor solution used for epitaxial growth is at least one of Bi, Na, R, K, Sr, Ce, Ca, Ba, Zn, Al, and Mn. After doping, a doped layer grows across the entire surface of the single crystal. The doped layer is then removed from certain areas by cutting and polishing, resulting in both doped and undoped regions on the surface of the single crystal.

[0011] Furthermore, the first electrode and the second electrode of the present invention are in ohmic contact with the perovskite single crystal, and are independently selected from one of Au, Ag, Al and Pt.

[0012] Furthermore, an illuminated area is formed on the surface of the perovskite single crystal by shading the remaining area. Furthermore, the shading is performed using insulating black tape, which covers all areas except the doped region between the first and second electrodes, and covers the portion of the doped region between the first and second electrodes that is adjacent to the first electrode, to ensure that there is a distance between the illuminated area and both the first and second electrodes. At the same time, transparent tape is placed between the insulating black tape and the single crystal at the position between the second electrode and the doped region.

[0013] Furthermore, the light source incident angle refers to the angle between the light source incident direction and the thickness direction of the single crystal (the absolute value is less than 90°, the light source incident angle is positive when the light source incident direction is toward the first electrode, and negative when the light source incident direction is toward the second electrode). The second wavelength refers to the peak wavelength when the light source incident angle is 0°, and the wavelength of light shorter than the second wavelength and having a linear relationship with the ratio of the photocurrent at the second wavelength when the light source incident angle changes is used as the first wavelength.

[0014] The method for manufacturing the angle measuring instrument based on the planar perovskite photodetector of the present invention can be implemented as follows:

[0015] 1) Synthesize perovskite single crystals as photosensitive substrates;

[0016] 2) Using an epitaxial growth method, a doped layer is grown on the surface of the perovskite single crystal, and the doped area except the top surface is cut (i.e., the doped area on the bottom surface and the side surface is removed). The doped layer is then removed from part of the top surface by sandpaper, so that both doped and undoped areas exist on the surface.

[0017] 3) Controlling the size and spacing of the illuminated area and electrodes on the surface of the perovskite single crystal through a metal mask;

[0018] 4) preparing two electrodes using electron beam evaporation or magnetron sputtering technology;

[0019] 5) Perform light shielding treatment on the remaining areas of the substrate surface except the illuminated area.

[0020] Compared with the prior art, the beneficial effects of the present invention are embodied in:

[0021] 1. The present invention provides a photoelectric angle measuring instrument based on a planar perovskite single crystal. The perovskite single crystal is used as a photosensitive substrate, a doped region is formed on the surface of the single crystal, and the relationship between the spectral response of the photodetector and the angle is utilized to establish a linear fitting function of the ratio of the short-wavelength photocurrent to the peak wavelength photocurrent and the illumination angle to achieve angle measurement. The measurement method is easy to implement, the device structure is simple, and there is no limit on the device size, which can realize the production of extremely small-sized devices.

[0022] 2. The angle measuring instrument of the present invention has the characteristics of low preparation cost, simple process and easy portability.

[0023] 3. The angle measuring instrument of the present invention has a planar structure, which is more conducive to integration than an angle measuring instrument with a vertical structure. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 This is a schematic structural diagram of an angle measuring instrument based on a planar perovskite single crystal provided in Example 1 of the present invention, wherein the numbers in the figure are: 1 is a perovskite single crystal; 2 is a doping region; 3 is a first electrode; 4 is a second electrode; 5 is an insulating black tape; 6 is an illumination region; and 7 is a transparent tape.

[0025] Figure 2 This is an SEM image of the MAPbBr3 single crystal with a thin Bi-doped layer prepared in Example 1 of the present invention.

[0026] Figure 3 This is a normalized photocurrent curve of the angle measuring instrument based on the planar perovskite single crystal obtained in this embodiment when the incident angle of the light source is positive.

[0027] Figure 4 This is a normalized photocurrent curve of the angle measuring instrument based on the planar perovskite single crystal obtained in this embodiment when the incident angle of the light source is negative.

[0028] Figure 5 This is a curve showing the relationship between the photocurrent ratio at a wavelength of 500 nm and a peak wavelength of 575 nm and the incident angle of the light source for the angle measuring instrument based on the planar perovskite single crystal provided in Example 1 of the present invention. DETAILED DESCRIPTION

[0029] The following is a detailed description of an embodiment of the present invention. This embodiment is implemented based on the technical solution of the present invention, and provides a detailed implementation method and specific operation process. However, the protection scope of the present invention is not limited to the following embodiment.

[0030] Example 1

[0031] like Figure 1As shown, this embodiment is based on a planar perovskite single crystal angle measuring instrument. A perovskite single crystal 1 is used as a photosensitive substrate. The single crystal surface is doped, resulting in both a doped region 2 and an undoped region. A first electrode 3 is disposed in the doped region, and a second electrode 4 is disposed in the undoped region. The perovskite single crystal surface is shielded from light by insulating black tape 5, forming an illuminated region 6. The insulating black tape covers all areas except the doped region between the first and second electrodes 3 and 4, and also covers the portion of the doped region adjacent to the first electrode between the first and second electrodes, ensuring a distance between the illuminated region and both the first and second electrodes. Furthermore, transparent tape 7 is provided between the insulating black tape and the single crystal at the position separating the second electrode 4 from the doped region. In this embodiment, Bi is doped on the surface of the MAPbBr3 single crystal to construct an angle measuring instrument. As the incident angle of the light source changes, the ratio of the device's photocurrent at the short wavelength to the peak wavelength changes linearly. Thus, the incident angle of the light source is determined based on the ratio of the photocurrents at the two wavelengths, enabling angle measurement.

[0032] Specifically, the photoelectric angle measuring instrument of this embodiment is manufactured according to the following steps:

[0033] (1) A P-type MAPbBr3 precursor solution was prepared from 0.112 g MABr, 0.367 g PbBr2, and 1 mL DMF solvent. The solution was grown on a heating plate at 80 °C for about 4 hours to obtain a P-type MAPbBr3 single crystal with a size of approximately 4 mm × 4 mm × 1 mm.

[0034] (2) The above single crystal was placed in a P-type MAPbBr3 precursor solution containing 0.3% BiBr3, sealed, and kept growing at 80°C for 30 minutes to finally obtain a MAPbBr3 single crystal with a thin Bi-doped layer on the surface, with a size of approximately 4 mm × 4 mm × 1 mm.

[0035] (3) The Bi-doped layer around and on the bottom of the single crystal was removed, and one-third of the Bi-doped layer on the upper surface of the MAPbBr3 single crystal was completely polished away using fine sandpaper to expose the undoped single crystal.

[0036] (4) There is a boundary line on the surface of the polished single crystal. Using the boundary line as a reference, silver wires of different diameters are used to control the position of the two electrodes. One electrode is located in the Bi-doped region, about 1 mm away from the polished boundary line, and the other electrode is located in the polished undoped region, about 100 μm away from the polished boundary line. Two gold electrodes of equal area and thickness of 50 nm are deposited on the surface of the perovskite using an electron beam evaporation device.

[0037] (5) Due to the small size of the device, it needs to be fixed on a PCB board with a slightly larger area. Wires are led out from the two electrodes for testing. Then, transparent tape 7 is set at the interval between the second electrode 4 and the doped area. Then, all areas of the single crystal surface except the doped area between the first electrode and the second electrode and the part of the doped area adjacent to the first electrode in the doped area between the first electrode and the second electrode are covered with insulating black tape 5 to form an illuminated area 6. The distance between the illuminated area and the first electrode is 0.5 mm, and the distance between the illuminated area and the second electrode is 100 μm.

[0038] Figure 2 This is an SEM image of the MAPbBr3 single crystal with a thin Bi-doped layer on the surface obtained in this embodiment. It can be seen from the figure that the Bi-doped area is located above the MAPbBr3 single crystal and the doping thickness is uniform.

[0039] The incident angle of the light source when the incident direction of the light source is toward the first electrode is a positive value, and the incident angle of the light source when the incident direction of the light source is toward the second electrode is a negative value.

[0040] Figure 3 This is the normalized photocurrent curve of the angle measuring instrument obtained in this embodiment when the incident angle of the light source is positive. Figure 4 This is the normalized photocurrent curve of the angle measuring instrument obtained in this embodiment when the incident angle of the light source is negative. Figure 3 and Figure 4 It can be seen that regardless of whether the tilt angle of the incident light is positive or negative, when the wavelength of the light is short (460-540nm), the photocurrent of the device increases with the increase of the tilt angle of the incident light. In particular, when the absolute value of the incident angle is greater than 40°, the short-wavelength photocurrent increases rapidly. This is because when the incident light is obliquely irradiated, the photogenerated carriers generated in the surface area of ​​the single crystal are closer to the electrode and are therefore easier to collect, and this phenomenon becomes more obvious as the tilt angle increases. In particular, when the incident angle is negative and tilted to a certain angle, part of the light will irradiate the P-type MAPbBr3 region. The number of defects in this region is significantly smaller than that in the Bi-doped region, and the recombination of carriers is relatively weak, which greatly increases the photocurrent of the device at short wavelengths.

[0041] For incident light with a longer wavelength (with a peak wavelength of 575nm as a reference), when the incident angle is positive, it can be seen that the photocurrent shows a monotonically decreasing trend as the deflection angle increases. This is because as the light tilt angle increases, the depth of the single crystal that can be penetrated by light with a longer wavelength becomes shallower, that is, the location where the photogenerated carriers are generated will be closer to the surface area. Affected by surface defects, the recombination of carriers intensifies, and ultimately leads to a decrease in the photocurrent. However, when the tilt angle of the incident charge is negative, the value of the photocurrent first decreases and then increases. This is also because part of the light irradiates the P-type MAPbBr3 region, and because long-wavelength light can penetrate deeper into the single crystal, it is less affected by surface defects, so the vast majority of the photogenerated carriers generated can be effectively collected by the electrode.

[0042] Figure 5 The relationship curve between the photocurrent ratio of the angle measuring instrument obtained in this embodiment at a wavelength of 500nm and a peak wavelength of 575nm and the incident angle of the light source can be seen from the figure: the ratio of the photocurrent of the device at a 500nm light source to the photocurrent of the device at a peak wavelength of 575nm is I 500 / I 575 It is linearly related to the incident angle θ of the light source. If the photocurrent of the detector is measured at 500nm and 575nm, calculate the current ratio I 500 / I 575 , then you can Figure 5 The incident angle of the light source can be obtained from the relationship curve.

[0043] The specific embodiments of the present invention described above do not limit the scope of protection of the present invention. Any other corresponding changes and modifications made based on the technical concept of the present invention should be included in the scope of protection of the claims of the present invention.

Claims

1. A photoelectric angle measuring instrument based on a planar perovskite single crystal, characterized by: The photoelectric angle measuring instrument uses a perovskite single crystal as a photosensitive substrate, doping a portion of the single crystal surface so that doped and undoped regions coexist on the single crystal surface. A first electrode is provided in the doped region, and a second electrode is provided in the undoped region. The doped region between the two electrodes is used as an illumination region. When the incident angle of the light source changes, the ratio of the photocurrent of the device at the first wavelength to the second wavelength changes linearly. Thus, the incident angle of the light source is obtained based on the ratio of the photocurrent at the first wavelength to the second wavelength.

2. The photoelectric angle measuring instrument based on planar perovskite single crystal according to claim 1, characterized in that: The perovskite single crystal is synthesized by a temperature gradient method, an anti-solvent vapor assisted crystallization process or a temperature inversion crystallization method.

3. The photoelectric angle measuring instrument based on planar perovskite single crystal according to claim 1, characterized in that: An illumination area is formed on the surface of the perovskite single crystal by performing light shielding treatment on the remaining areas.

4. The photoelectric angle measuring instrument based on a planar perovskite single crystal according to claim 3, characterized in that: Light shading is performed by using insulating black tape, which covers all areas except the doped area between the first electrode and the second electrode, and covers part of the doped area adjacent to the first electrode in the doped area between the first electrode and the second electrode, so as to ensure that there is a distance between the illuminated area and both the first electrode and the second electrode; at the same time, transparent tape is set between the insulating black tape and the single crystal at the interval between the second electrode and the doped area.

5. The photoelectric angle measuring instrument based on planar perovskite single crystal according to claim 1, characterized in that: The doping is accomplished by placing the single crystal into a perovskite precursor solution containing doping elements for epitaxial growth.

6. The photoelectric angle measuring instrument based on planar perovskite single crystal according to claim 1, characterized in that: The light source incident angle refers to the angle between the light source incident direction and the thickness direction of the single crystal.

7. The photoelectric angle measuring instrument based on a planar perovskite single crystal according to claim 1 or 6, characterized in that: The second wavelength refers to the peak wavelength when the incident angle of the light source is 0°, and a light wavelength shorter than the second wavelength and having a linear relationship with the ratio of the photocurrent at the second wavelength when the incident angle of the light source changes is used as the first wavelength.

8. The photoelectric angle measuring instrument based on planar perovskite single crystal according to claim 1, characterized in that: The perovskite single crystal is one of MAPbBr3, MAPbI3 and MAPbCl3.

9. The photoelectric angle measuring instrument based on planar perovskite single crystal according to claim 1 or 8, characterized in that: The doping element is at least one of Bi, Na, R, K, Sr, Ce, Ca, Ba, Zn, Al and Mn.

10. The photoelectric angle measuring instrument based on planar perovskite single crystal according to claim 1, characterized in that: The first electrode and the second electrode are in ohmic contact with the perovskite single crystal, and are independently selected from one of Au, Ag, Al and Pt.

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