Ultraviolet photoelectric detector and preparation method thereof

Abstract

The invention discloses an ultraviolet photoelectric detector and a preparation method thereof, which can be widely applied to the technical field of detectors. According to the ultraviolet photoelectric detector, the photosensitive device, the signal amplification device, the signal processing device and the signal display device are arranged in the ultraviolet photoelectric detector, and the substrate, the bottom electrode layer, the ferroelectric semiconductor layer, the insulating layer and the top electrode are arranged in the photosensitive device, so that the forbidden bandwidth characteristic of the ferroelectric semiconductor layer can be utilized; the detection capability of the ultraviolet photoelectric detector on ultraviolet light is improved, an optical filter does not need to be added, and the manufacturing cost is effectively reduced; and the substrate, the bottom electrode layer, the ferroelectric semiconductor layer and the top electrode form a vertical structure, and the thickness between the electrodes is effectively reduced, so that extremely high write-in electric field intensity can be obtained by adopting extremely low write-in voltage, photon-generated carriers are more effectively separated, light current is enhanced, and the working performance of the device is improved.

Description

Technical Field

[0001] The present application relates to the field of detector technology, and in particular to an ultraviolet photoelectric detector and a preparation method thereof. Background Art

[0002] In the related art, the ultraviolet detector is a sensor that can detect the intensity of ultraviolet light, which is used to detect the intensity and energy of ultraviolet light radiation. The current ultraviolet detectors are basically silicon-based ultraviolet detectors and wide-bandgap semiconductor ultraviolet detectors, and the principle is to use the photoelectric effect, that is, the phenomenon that photons excite electrons to transition to the conduction band to generate current. Since the bandgap width of silicon semiconductors is 1.2eV, it responds to ultraviolet light, visible light, and near-infrared light, so as an ultraviolet photodetector, the response speed is slow, and additional filters need to be installed. However, the filter is expensive and easy to damage, which increases the cost and loss of the ultraviolet detector. In addition, gallium nitride (GaN), as a representative of wide-bandgap semiconductors, is an ideal material for preparing detectors, but because the n-type semiconductor material layer such as GaN is usually combined with other material layers, there is a large lattice mismatch, resulting in large defects in the material layer interface, thereby reducing the performance of the ultraviolet detector.

[0003] In summary, the technical problems existing in the relevant technologies need to be improved. Summary of the invention

[0004] The main purpose of the embodiments of the present application is to provide an ultraviolet photodetector and a method for preparing the same, which can effectively reduce manufacturing costs and improve working performance.

[0005] To achieve the above purpose, an embodiment of the present application provides an ultraviolet photodetector, the ultraviolet photodetector comprising:

[0006] A photosensitive device, the photosensitive device comprising a substrate, a bottom electrode layer, a ferroelectric semiconductor layer, an insulating layer and a top electrode, wherein the substrate, the bottom electrode layer, the ferroelectric semiconductor layer and the top electrode form a vertical structure, and the insulating layer is arranged on the side of the top electrode and on the top of the ferroelectric semiconductor layer;

[0007] A signal amplifier device, the signal amplifier device is used to receive the photosensitive current output by the photosensitive device;

[0008] A signal processing device, the signal processing device is used to perform data processing on the photosensitive current to obtain light intensity;

[0009] A signal display device is used to display the light intensity output by the signal processing device.

[0010] In some embodiments, the material of the ferroelectric semiconductor layer includes a ferroelectric semiconductor material having a perovskite structure.

[0011] In some embodiments, the ferroelectric semiconductor material having a perovskite structure includes lead zirconate titanate.

[0012] In some embodiments, the thickness of the ferroelectric semiconductor layer is in a range of greater than or equal to 155 nm and less than or equal to 165 nm.

[0013] In some embodiments, the thickness of the ferroelectric semiconductor layer comprises 160 nm.

[0014] In some embodiments, the material of the substrate includes strontium titanate, and the thickness of the substrate includes 80 nm.

[0015] In some embodiments, the material of the bottom electrode layer includes a perovskite structure oxide having metallic conductivity.

[0016] In some embodiments, the insulating layer is made of at least one of a single-layer silicon oxide, a multi-layer silicon oxide, a single-layer silicon nitride, or a multi-layer silicon nitride.

[0017] In some embodiments, the material of the top electrode includes one of indium, silver, gold, copper, chromium, or a gold-tin alloy.

[0018] To achieve the above object, another aspect of the embodiment of the present application provides a method for preparing an ultraviolet photodetector, the method comprising the following steps:

[0019] preparing a signal display device;

[0020] Prepare a signal processing device, and connect the output end of the signal processing device to the signal display device;

[0021] Prepare a signal amplifying device, and connect the output end of the signal amplifying device to the signal processing device;

[0022] Prepare a photosensitive device, and connect the input end of the signal amplifier device to the output end of the photosensitive device;

[0023] The process of preparing the photosensitive device comprises the following steps:

[0024] preparing a substrate;

[0025] preparing a bottom electrode layer on the substrate by pulsed laser deposition;

[0026] preparing a ferroelectric semiconductor layer on the bottom electrode layer by pulsed laser deposition;

[0027] Spin coating an organic resin on the ferroelectric semiconductor layer by using a coating machine and drying the resin to form an insulating layer;

[0028] The ferroelectric semiconductor layer is exposed at a preset position of the insulating layer, and a top electrode is grown by magnetron sputtering; the substrate, the bottom electrode layer, the ferroelectric semiconductor layer and the top electrode form a vertical structure.

[0029] The embodiments of the present application include at least the following beneficial effects: The present application provides an ultraviolet photodetector and a method for preparing the same, which arranges a photosensitive device, a signal amplifier device, a signal processing device and a signal display device in the ultraviolet photodetector, and arranges a substrate, a bottom electrode layer, a ferroelectric semiconductor layer, an insulating layer and a top electrode in the photosensitive device, thereby utilizing the bandgap width characteristics of the ferroelectric semiconductor layer to improve the detection capability of the ultraviolet photodetector for ultraviolet light without adding a filter, thereby effectively reducing the manufacturing cost; and the substrate, the bottom electrode layer, the ferroelectric semiconductor layer and the top electrode form a vertical structure, thereby effectively reducing the thickness between the electrodes, thereby being able to use an extremely low write voltage to obtain an extremely high write electric field strength, so that photogenerated carriers can be separated more effectively, the photocurrent is enhanced, and the device operating performance is improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 Schematic diagram of a module of an ultraviolet photodetector provided in an embodiment of the present application;

[0031] Figure 2 is a schematic structural diagram of a photosensitive device provided in an embodiment of the present application;

[0032] Figure 3 It is an It diagram of the ultraviolet photodetector provided in the embodiment of the present application under irradiation with different light power densities at 365 nm;

[0033] Figure 4 It is an It graph of the ultraviolet photodetector provided in the embodiment of the present application under irradiation of 365nm and 100mW / cm2;

[0034] Figure 5 Schematic diagram of the response of the ultraviolet photodetector provided in the embodiment of the present application at 0V and 365nm;

[0035] Figure 6 is a schematic diagram of the light response of the ultraviolet photodetector provided in the embodiment of the present application at different wavelengths;

[0036] Figure 7 It is a schematic diagram comparing the performance of the ultraviolet photodetector provided in the embodiment of the present application with Si-based and GaN-based photodetectors. DETAILED DESCRIPTION

[0037] In order to make the purpose, technical solutions and advantages of the present application clearer, the present application is further described in detail below in conjunction with the accompanying drawings and examples. It should be understood that the specific embodiments described herein are only used to explain the present application and are not intended to limit the present application. When the following description refers to the drawings, unless otherwise indicated, the same numbers in different drawings represent the same or similar elements. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with the embodiments of the present application, they are only examples of devices and methods consistent with some aspects of the embodiments of the present application.

[0038] It is understood that the terms "first", "second", etc. used in this application can be used to describe various concepts in this article, but unless otherwise specified, these concepts are not limited by these terms. These terms are only used to distinguish one concept from another concept. For example, without departing from the scope of the embodiment of the present application, the first information may also be referred to as the second information, and similarly, the second information may also be referred to as the first information. Depending on the context, the words "if" and "if" as used herein can be interpreted as "at the time of" or "when" or "in response to determination".

[0039] The terms "at least one", "multiple", "each", "any", etc. used in this application, at least one includes one, two or more, multiple includes two or more, each refers to each of the corresponding multiple, and any refers to any one of the multiple.

[0040] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art to which this application belongs. The terms used herein are only for the purpose of describing the embodiments of this application and are not intended to limit this application.

[0041] In the related art, the ultraviolet detector is a sensor that can detect the intensity of ultraviolet light, which is used to detect the intensity and energy of ultraviolet light radiation. The current ultraviolet detectors are basically silicon-based ultraviolet detectors and wide-bandgap semiconductor ultraviolet detectors, and the principle is to use the photoelectric effect, that is, the phenomenon that photons excite electrons to transition to the conduction band to generate current. Since the bandgap width of silicon semiconductors is 1.2eV, it responds to ultraviolet light, visible light, and near-infrared light, so as an ultraviolet photodetector, the response speed is slow, and additional filters need to be installed. However, the filter is expensive and easy to damage, which increases the cost and loss of the ultraviolet detector. In addition, gallium nitride (GaN), as a representative of wide-bandgap semiconductors, is an ideal material for preparing detectors, but because the n-type semiconductor material layer such as GaN is usually combined with other material layers, there is a large lattice mismatch, resulting in large defects in the material layer interface, thereby reducing the performance of the ultraviolet detector.

[0042] In view of this, an ultraviolet photodetector and a preparation method thereof are provided in an embodiment of the present application. The present application arranges a photosensitive device, a signal amplifier device, a signal processing device and a signal display device in the ultraviolet photodetector, and arranges a substrate, a bottom electrode layer, a ferroelectric semiconductor layer, an insulating layer and a top electrode in the photosensitive device, thereby utilizing the bandgap width characteristics of the ferroelectric semiconductor layer to improve the detection capability of the ultraviolet photodetector for ultraviolet light without adding a filter, thereby effectively reducing the manufacturing cost; and the substrate, the bottom electrode layer, the ferroelectric semiconductor layer and the top electrode form a vertical structure, effectively reducing the thickness between the electrodes, thereby being able to use an extremely low write voltage to obtain an extremely high write electric field strength, so that photogenerated carriers can be separated more effectively, the photocurrent is enhanced, and the device performance is improved.

[0043] The ultraviolet photoelectric detector of the present application is described below in conjunction with the accompanying drawings:

[0044] Reference Figure 1 The present application discloses an ultraviolet photodetector, which includes a photosensitive device, a signal amplifier, a signal processing device, and a signal display device. The signal amplifier is used to receive the photosensitive current output by the photosensitive device, the signal processing device is used to process the photosensitive current to obtain the light intensity, and the signal display device is used to display the light intensity output by the signal processing device. It can be understood that if Figure 2 As shown, the photosensitive device includes a substrate 210, a bottom electrode layer 220, a ferroelectric semiconductor layer 230, an insulating layer 240 and a top electrode 250. The substrate 210, the bottom electrode layer 220, the ferroelectric semiconductor layer 230 and the top electrode 250 form a vertical structure, and the insulating layer 240 is arranged on the side of the top electrode 250 and on the ferroelectric semiconductor layer 230, so that the bandgap width characteristics of the ferroelectric semiconductor layer can be used to improve the detection capability of the ultraviolet photodetector to ultraviolet light, without adding filters, and effectively reducing the manufacturing cost.

[0045] It is understandable that if Figure 1 As shown, the signal amplifier device can use a transimpedance amplifier to amplify the electrical signal formed by the photosensitive device for receiving the photoelectrons (hv). The signal processing device includes a digital-to-analog converter, a CPU, an I / O output, and a power module. The amplified signal of the signal amplifier device is converted into a digital signal through the digital-to-analog converter, and after being read and processed by the CPU, the light intensity is displayed on the LED display screen of the signal display device through the I / O output. The power module is used to provide working power.

[0046] In the embodiment of the present application, the material of the ferroelectric semiconductor layer includes a ferroelectric semiconductor material with a perovskite structure, and lead zirconate titanate (PZT) can be selected specifically. It is understandable that PZT, as a mature ferroelectric semiconductor material, has excellent stability. After polarization, it will generate a built-in electric field that runs through the body region, which can quickly separate photogenerated carriers and achieve self-power supply. It does not require the use of an external electric field, has a small dark current, can accurately detect weak ultraviolet signals, and the response speed of the detector is improved. In addition, the bandgap width of PZT is 3.6eV, and it only responds to the ultraviolet region, thereby improving the detection capability of ultraviolet photodetectors to ultraviolet light without the need for additional filters.

[0047] In the embodiment of the present application, the thickness of the ferroelectric semiconductor layer is greater than or equal to 155nm and less than or equal to 165nm. The thickness of the ferroelectric semiconductor layer can be specifically set to 160nm, and combined with the vertical structure formed between the layers, compared with the conventional horizontal structure detector, the distance between the electrodes of the vertical structure is only the thickness of the ferroelectric semiconductor layer, so that a very high write electric field strength can be obtained with a very low write voltage, so that the photogenerated carriers are separated more effectively and the photocurrent formed by the detector is enhanced.

[0048] In the embodiment of the present application, the substrate material can be strontium titanate (SrTiO3), and the substrate thickness can be set to 80nm. Among them, SrTiO3 single crystal has a good lattice structure of perovskite structural materials, is an excellent substrate material, and can effectively improve the detection stability of the detector.

[0049] In the embodiment of the present application, the material of the bottom electrode layer includes a perovskite structure oxide with metallic conductivity, which has excellent electrical properties, and SrRuO3 (SRO for short) can be selected. Specifically, the room temperature resistivity of SRO is 280μΩ*cm, and it has high electrical conductivity, high chemical stability and thermal stability, and has a similar lattice structure and good lattice matching with ferroelectric thin films (PZT, BST), thereby improving the working performance of the detector.

[0050] In the embodiment of the present application, the material of the insulating layer includes at least one of a single-layer silicon oxide, a multi-layer silicon oxide, a single-layer silicon nitride or a multi-layer silicon nitride, and the composition of the specific materials can be combined according to actual conditions. The material of the top electrode includes one of indium, silver, gold, copper, chromium or a gold-tin alloy.

[0051] In the present embodiment, Figure 1 The ultraviolet photodetector shown in the figure is tested and it is known that Figure 3 It can be seen that the light intensity of the ultraviolet photodetector of the present application under different light power densities at 365nm is linearly related to the current. Figure 4It can be seen that the photocurrent of the ultraviolet photodetector of the present application can maintain a stable reading for a long time under 365nm and 100mW / cm2 irradiation. Figure 5 It can be seen that the ultraviolet photodetector of the present application has a fast response speed at 0V and 365nm. Figure 6 It can be seen that the ultraviolet photodetector of the present application only responds to ultraviolet light at different wavelengths. Figure 7 It can be seen that the ultraviolet photodetector of the present application has the best performance under the same test conditions as the Si-based and GaN-based photodetectors.

[0052] In addition, the present application also provides a method for Figure 1 The method for preparing the ultraviolet photodetector comprises the following steps:

[0053] preparing a signal display device;

[0054] Prepare a signal processing device, and connect the output end of the signal processing device to the signal display device;

[0055] Prepare a signal amplifying device, and connect the output end of the signal amplifying device to the signal processing device;

[0056] Prepare a photosensitive device, and connect the input end of the signal amplifier device to the output end of the photosensitive device;

[0057] The process of preparing the photosensitive device includes the following steps:

[0058] preparing a substrate;

[0059] preparing a bottom electrode layer on the substrate by pulsed laser deposition;

[0060] A ferroelectric semiconductor layer is prepared on the bottom electrode layer by pulsed laser deposition;

[0061] Spinning an organic resin on the ferroelectric semiconductor layer using a coating machine and drying the resin to form an insulating layer;

[0062] The ferroelectric semiconductor layer is exposed at a preset position of the insulating layer, and a top electrode is grown by magnetron sputtering; wherein the substrate, the bottom electrode layer, the ferroelectric semiconductor layer and the top electrode form a vertical structure.

[0063] It can be understood that the contents of the above detector embodiments are all applicable to the present method embodiments, the functions specifically implemented by the present method embodiments are the same as those of the above detector embodiments, and the beneficial effects achieved are also the same as those achieved by the above detector embodiments.

[0064] The embodiments described in the embodiments of the present application are intended to more clearly illustrate the technical solutions of the embodiments of the present application and do not constitute a limitation on the technical solutions provided in the embodiments of the present application. Those skilled in the art will appreciate that with the evolution of technology and the emergence of new application scenarios, the technical solutions provided in the embodiments of the present application are also applicable to similar technical problems.

[0065] Those skilled in the art will appreciate that the technical solutions shown in the figures do not constitute a limitation on the embodiments of the present application, and may include more or fewer steps than shown in the figures, or a combination of certain steps, or different steps.

[0066] The device embodiments described above are merely illustrative, and the units described as separate components may or may not be physically separated, that is, they may be located in one place or distributed on multiple network units. Some or all of the modules may be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0067] Those skilled in the art will appreciate that all or some of the steps in the methods disclosed above, and the functional modules / units in the systems and devices may be implemented as software, firmware, hardware, or a suitable combination thereof.

[0068] The terms "first", "second", "third", "fourth", etc. (if any) in the specification of the present application and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the data used in this way can be interchangeable where appropriate, so that the embodiments of the present application described herein can be implemented in an order other than those illustrated or described herein. In addition, the terms "including" and "having" and any of their variations are intended to cover non-exclusive inclusions, for example, a process, method, system, product or device comprising a series of steps or units is not necessarily limited to those steps or units clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0069] It should be understood that in the present application, "at least one (item)" means one or more, and "plurality" means two or more. "And / or" is used to describe the association relationship of associated objects, indicating that three relationships may exist. For example, "A and / or B" can mean: only A exists, only B exists, and A and B exist at the same time, where A and B can be singular or plural. The character " / " generally indicates that the objects associated before and after are in an "or" relationship. "At least one of the following" or similar expressions refers to any combination of these items, including any combination of single or plural items. For example, at least one of a, b or c can mean: a, b, c, "a and b", "a and c", "b and c", or "a and b and c", where a, b, c can be single or multiple.

[0070] The units described above as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed on multiple network units. Some or all of the units may be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0071] The preferred embodiments of the present invention are described above with reference to the accompanying drawings, but the scope of the rights of the present invention is not limited thereto. Any modification, equivalent substitution and improvement made by a person skilled in the art without departing from the scope and essence of the present invention should be within the scope of the rights of the present invention.

Claims

1. An ultraviolet photoelectric detector, characterized in that: The ultraviolet photodetector comprises: A photosensitive device, the photosensitive device comprising a substrate, a bottom electrode layer, a ferroelectric semiconductor layer, an insulating layer and a top electrode, wherein the substrate, the bottom electrode layer, the ferroelectric semiconductor layer and the top electrode form a vertical structure, and the insulating layer is arranged on the side of the top electrode and on the top of the ferroelectric semiconductor layer; A signal amplifier device, the signal amplifier device is used to receive the photosensitive current output by the photosensitive device; A signal processing device, the signal processing device is used to perform data processing on the photosensitive current to obtain light intensity; A signal display device is used to display the light intensity output by the signal processing device.

2. The method according to claim 1, characterized in that The material of the ferroelectric semiconductor layer includes a ferroelectric semiconductor material having a perovskite structure.

3. The method according to claim 2, characterized in that The ferroelectric semiconductor material having a perovskite structure includes lead zirconate titanate.

4. The method according to claim 3, characterized in that The thickness of the ferroelectric semiconductor layer is in the range of greater than or equal to 155 nm and less than or equal to 165 nm.

5. The method according to claim 4, characterized in that The thickness of the ferroelectric semiconductor layer is comprised of 160 nm.

6. The method according to claim 1, characterized in that The material of the substrate includes strontium titanate, and the thickness of the substrate includes 80 nm.

7. The method according to claim 1, characterized in that The material of the bottom electrode layer includes a perovskite structure oxide having metallic conductivity.

8. The method according to claim 1, characterized in that: The material of the insulating layer includes at least one of a single-layer silicon oxide, a multi-layer silicon oxide, a single-layer silicon nitride, or a multi-layer silicon nitride.

9. The method according to claim 1, characterized in that: The material of the top electrode includes one of indium, silver, gold, copper, chromium or gold-tin alloy.

10. A method for preparing an ultraviolet photodetector, characterized in that: The method comprises the following steps: preparing a signal display device; Prepare a signal processing device, and connect the output end of the signal processing device to the signal display device; Prepare a signal amplifying device, and connect the output end of the signal amplifying device to the signal processing device; Prepare a photosensitive device, and connect the input end of the signal amplifier device to the output end of the photosensitive device; The process of preparing the photosensitive device comprises the following steps: preparing a substrate; preparing a bottom electrode layer on the substrate by pulsed laser deposition; preparing a ferroelectric semiconductor layer on the bottom electrode layer by pulsed laser deposition; Spin coating an organic resin on the ferroelectric semiconductor layer by using a coating machine and drying the resin to form an insulating layer; The ferroelectric semiconductor layer is exposed at a preset position of the insulating layer, and a top electrode is grown by magnetron sputtering; the substrate, the bottom electrode layer, the ferroelectric semiconductor layer and the top electrode form a vertical structure.

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