Phototransistor, preparation method thereof and photoelectric detector
By designing phototransistors with different band gap widths, gate voltage distribution is used to identify light of different bands, which solves the problem that traditional photodetectors are difficult to identify two-color light, reduces manufacturing difficulty and cost, and improves device integration.
Patent Information
- Application Number
- CN202310781178.3
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2023-06-28
- Publication Date
- 2024-12-31
AI Technical Summary
Traditional single-pixel photodetectors can only detect monochromatic light. To achieve the identification and detection of two-color light, two single-pixel photodetectors with different response bands need to be combined or equipped with different filters, which is difficult and cost-effective. And the device integration is low.
Design a phototransistor, including a substrate, a source electrode, a drain electrode, a channel layer, an insulating dielectric layer and a semiconductor layer, and by setting the band gap width of the semiconductor layer is greater than the band gap width of the channel layer, the gate voltage distribution is achieved. For optical recognition in different bands, the semiconductor layer plays a dominant role at shorter wavelengths, and the channel layer plays a dominant role at longer wavelengths, achieving dual-color recognition through the magnitude relationship between photocurrent and dark current.
The light recognition of different wavelength bands is realized through a single device, which reduces manufacturing difficulty and cost, improves the integration of the device, and can effectively identify light of different wavelengths.
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Figure CN119230644A_ABST
Abstract
Description
Technical Field
[0001] The present application relates to the field of transistor technology, and in particular to a phototransistor and a preparation method thereof, and a photodetection device. Background Art
[0002] Photodetectors have a wide range of uses. They are mainly used for ray measurement, ray detection, industrial automatic control, photometry, etc. in the visible light or near-infrared bands. With the development of the Internet of Things, the demand for photodetectors is increasing. However, traditional single-pixel photodetectors can only detect monochromatic light. To achieve the recognition and detection of two-color light, it is necessary to combine two single-pixel photodetectors with different response bands or to equip two identical single-pixel photodetectors with two different filters. This implementation method is difficult and costly to manufacture, and the device integration is low. Summary of the invention
[0003] Based on this, it is necessary to provide a phototransistor and a method for manufacturing the same, and a photodetection device. The phototransistor can realize the recognition of light of different wavelength bands through a single device.
[0004] In a first aspect, the present application provides a phototransistor, comprising a substrate, a source electrode, a drain electrode, a channel layer, an insulating dielectric layer, a semiconductor layer and a gate electrode; the source electrode and the drain electrode are arranged on a surface of the substrate with an interval; the channel layer is arranged on the surface of the substrate and is located between the source electrode and the drain electrode, and the channel layer is connected to the source electrode and the drain electrode; the insulating dielectric layer, the semiconductor layer and the gate electrode are sequentially stacked on the surface of the channel layer away from the substrate; the band gap width of the semiconductor layer is greater than the band gap width of the channel layer.
[0005] In some embodiments, a difference between a band gap width of the semiconductor layer and a band gap width of the channel layer is greater than or equal to 0.2 eV.
[0006] In some embodiments, the bandgap width of the channel layer is 0.2 eV to 5 eV.
[0007] In some embodiments, the band gap width of the semiconductor layer is 1.5 eV~5.5 eV.
[0008] In some embodiments, the resistance of the semiconductor layer in a dark state is greater than or equal to 1% of the resistance of the insulating dielectric layer.
[0009] In some embodiments, the semiconductor layer has a thickness of 20 nm to 1000 nm.
[0010] In some embodiments, the channel layer partially or entirely covers a surface of the source electrode away from the substrate.
[0011] In some embodiments, the channel layer partially or entirely covers a surface of the drain electrode away from the substrate.
[0012] In some embodiments, the insulating dielectric layer partially or entirely covers a surface of the source electrode away from the substrate.
[0013] In some embodiments, the insulating dielectric layer partially or entirely covers a surface of the drain electrode away from the substrate.
[0014] In some embodiments, the insulating dielectric layer partially or completely covers the surface of the substrate where the source electrode, the drain electrode and the channel layer are not provided.
[0015] In some embodiments, the material of the channel layer is selected from at least one of silicon, molybdenum disulfide, tungsten disulfide, rhenium disulfide, tungsten diselenide, indium gallium zinc oxide, gallium oxide, gallium arsenide, indium selenide and an organic semiconductor.
[0016] In some embodiments, the material of the semiconductor layer is selected from at least one of silicon, molybdenum disulfide, tungsten disulfide, rhenium disulfide, tungsten diselenide, indium gallium zinc oxide, gallium oxide, gallium arsenide, indium selenide and an organic semiconductor.
[0017] In some embodiments, the material of the insulating dielectric layer is selected from at least one of silicon dioxide, silicon nitride, aluminum oxide, hafnium dioxide, titanium dioxide, polyethylene naphthalate, polyethylene terephthalate, polyimide, polymethyl methacrylate, polydimethylsiloxane, polyvinyl chloride, polycarbonate, polystyrene and polymethyl methacrylate.
[0018] In some embodiments, the source electrode, the drain electrode, and the gate electrode are each independently selected from at least one of metal electrodes.
[0019] In some embodiments, the material of the substrate is selected from at least one of silicon, silicon oxide, sapphire, glass, ceramic, polyethylene naphthalate, polyethylene terephthalate, polyimide, polymethyl methacrylate, polydimethylsiloxane, polyvinyl chloride, polycarbonate, polystyrene and polymethyl methacrylate.
[0020] In a second aspect, the present application also provides a method for preparing a phototransistor, comprising: providing a substrate; preparing a source electrode, a drain electrode and a channel layer on one surface of the substrate, respectively, the source electrode and the drain electrode being arranged at intervals, the channel layer being located between the source electrode and the drain electrode and being connected to the source electrode and the drain electrode; preparing an insulating dielectric layer, a semiconductor layer and a gate electrode stacked in sequence on a surface of the channel layer away from the substrate, the band gap width of the semiconductor layer being greater than the band gap width of the channel layer.
[0021] In a third aspect, the present application further provides a photoelectric detection device, comprising any of the above-mentioned phototransistors or a phototransistor prepared by the above-mentioned method for preparing a phototransistor.
[0022] The above-mentioned phototransistor includes a semiconductor layer located between an insulating dielectric layer and a gate electrode, and the width of the band gap of the semiconductor layer is greater than the band gap width of the channel layer. The phototransistor can realize the recognition of light of different wavelengths by gate voltage distribution. Under the irradiation of light with a relatively short wavelength, the semiconductor layer plays a major role, resulting in the redistribution of the gate voltage. Under the irradiation of light with a relatively long wavelength, the channel layer plays a major role, resulting in an increase in the channel carrier concentration, that is, under the irradiation of light with different wavelengths, according to the magnitude relationship between the photocurrent and the dark current, the recognition of light of different wavelengths can be realized. BRIEF DESCRIPTION OF THE DRAWINGS
[0023] Figure 1 A schematic diagram of the structure of a phototransistor provided in one embodiment of the present application;
[0024] Figure 2 A schematic diagram of an equivalent circuit of a semiconductor layer and an insulating dielectric layer of a phototransistor provided in an embodiment of the present application;
[0025] Figure 3 The response curve of the phototransistor provided in Example 1 of the present application to 254nm light;
[0026] Figure 4 This is the response curve of the phototransistor provided in Example 1 of the present application to 365nm light.
[0027] Description of Reference Numerals
[0028] 11. substrate; 21. source electrode; 22. drain electrode; 31. channel layer; 41. insulating dielectric layer; 51. semiconductor layer; 61. gate electrode. DETAILED DESCRIPTION
[0029] In order to make the above-mentioned purposes, features and advantages of the present application more obvious and easy to understand, the specific implementation methods of the present application are described in detail below in conjunction with the accompanying drawings. In the following description, many specific details are set forth to facilitate a full understanding of the present application. However, the present application can be implemented in many other ways different from those described herein, and those skilled in the art can make similar improvements without violating the connotation of the present application, so the present application is not limited by the specific embodiments disclosed below.
[0030] 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 in the specification of this application are only for the purpose of describing specific embodiments and are not intended to limit this application. The term "and / or" used herein includes any and all combinations of one or more of the related listed items.
[0031] Reference Figure 1 An embodiment of the present application provides a phototransistor, including a substrate 11, a source electrode 21, a drain electrode 22, a channel layer 31, an insulating dielectric layer 41, a semiconductor layer 51 and a gate electrode 61; the source electrode 21 and the drain electrode 22 are arranged on a surface of the substrate 11 at intervals; the channel layer 31 is arranged on the surface of the substrate 11 and is located between the source electrode 21 and the drain electrode 22, and the channel layer 31 is connected to the source electrode 21 and the drain electrode 22; an insulating dielectric layer 41, a semiconductor layer 51 and a gate electrode 61 are sequentially stacked on the surface of the channel layer 31 away from the substrate 11; the band gap width of the semiconductor layer 51 is greater than the band gap width of the channel layer 31.
[0032] The above-mentioned phototransistor includes a semiconductor layer 51 located between the insulating dielectric layer 41 and the gate electrode 61, and the width of the band gap of the semiconductor layer 51 is greater than the band gap width of the channel layer 31. The phototransistor can realize the recognition of light of different wavelengths by gate voltage distribution. Under the irradiation of light with a relatively short wavelength, the semiconductor layer 51 plays a major role, resulting in the redistribution of the gate voltage. Under the irradiation of light with a relatively long wavelength, the channel layer 31 plays a major role, resulting in an increase in the channel carrier concentration, that is, under the irradiation of light with two different wavelengths, according to the magnitude relationship between the photocurrent and the dark current, the recognition of light of different wavelengths can be realized. Furthermore, by setting different materials of the channel layer 31 and the semiconductor layer 51, the recognition of light of different wavelength combinations can be realized.
[0033] The detection principle of the phototransistor in this scheme is explained in detail below.
[0034] In the dark state, the equivalent circuit and gate voltage distribution of the semiconductor layer 51 and the insulating dielectric layer 41 are as follows: Figure 2 As shown, C 51 and R 51 are the equivalent capacitance and resistance of the semiconductor layer 51, C 41 and R 41 are the equivalent capacitance and resistance of the insulating dielectric layer 41 respectively. The gate voltage is fixed to V GS , the gate voltage borne by the semiconductor layer 51 is V 51 , then the gate voltage borne by the insulating dielectric layer 41 is V 41 =V GS -V 51, so the amount of electron charge depleted in the channel layer 31 is Q=C 41 ×(V GS -V 51 ). Under the irradiation of light with a shorter wavelength (i.e., matching the band gap of the semiconductor layer 51), the resistance of the semiconductor layer 51 decreases significantly. The resistance of the semiconductor layer 51 after the decrease is negligible compared with the resistance of the insulating dielectric layer 41. At this time, the gate voltage is almost entirely distributed on the insulating dielectric layer 41, i.e., V 41 =V GS , so the electron charge of the channel depletion is Q=C 41 ×V GS , at this time, the photocurrent will be lower than the dark current. Under the irradiation of light with a longer wavelength (i.e., matching the band gap of the channel layer 31), the resistance of the semiconductor layer 51 remains unchanged, so the relationship of the gate voltage distribution remains unchanged, and the channel layer 31 will generate carriers, resulting in a photocurrent higher than the dark current. By comparing the size of the photocurrent and the dark current, it is possible to distinguish between light of different wavelengths, that is, to achieve dual-color recognition.
[0035] In some embodiments, the difference between the bandgap width of the semiconductor layer 51 and the bandgap width of the channel layer 31 is greater than or equal to 0.2 eV. When the difference between the bandgap width of the semiconductor layer 51 and the bandgap width of the channel layer 31 is greater than or equal to 0.2 eV, it is easier to distinguish the wavelength, and the effect of identifying light of different wavelengths is better. Optionally, the difference between the bandgap width of the semiconductor layer 51 and the bandgap width of the channel layer 31 is 0.2 eV~5.3 eV. Further optionally, the difference between the band gap width of the semiconductor layer 51 and the band gap width of the channel layer 31 is 0.2eV, 0.3eV, 0.4eV, 0.5eV, 0.6eV, 0.7eV, 0.8eV, 0.9eV, 1.0eV, 1.1eV, 1.2eV, 1.3eV, 1.4eV, 1.5eV, 1.6eV, 1.7eV, 1.8eV, 1.9eV, 2.0eV, 2.1eV, 2.2eV, 2.3eV, 2.4eV, 2 .5eV, 2.6eV, 2.7eV, 2.8eV, 2.9eV, 3.0eV, 3.1eV, 3.2eV, 3.3eV, 3.4eV, 3.5eV, 3.6eV, 3.7eV, 3.8eV, 3.9 eV, 4.0eV, 4.1eV, 4.2eV, 4.3eV, 4.4eV, 4.5eV, 4.6eV, 4.7eV, 4.8eV, 4.9eV, 5.0eV, 5.1eV, 5.2eV or 5.3eV.
[0036] In some embodiments, the bandgap width of the channel layer 31 is 0.2eV to 5eV. Optionally, the bandgap width of the channel layer 31 is 0.2eV, 0.3eV, 0.4eV, 0.5eV, 0.6eV, 0.7eV, 0.8eV, 0.9eV, 1.0eV, 1.1eV, 1.2eV, 1.3eV, 1.4eV, 1.5eV, 1.6eV, 1.7eV, 1.8eV, 1.9eV, 2.0eV, 2.1eV, 2.2eV, 2.3eV, 2.4eV, 2.5eV, 2.6eV, 2.7eV, 2.8eV, 2.9eV, 3.0eV, 3.1eV, 3.2eV, 3.3eV, 3.4eV, 3.5eV, 3.6eV, 3.7eV , 3.8eV, 3.9eV, 4.0eV, 4.1eV, 4.2eV, 4.3eV, 4.4eV, 4.5eV, 4.6eV, 4.7eV, 4.8eV, 4.9eV or 5eV.
[0037] In some embodiments, the bandgap width of the semiconductor layer 51 is 1.5 eV to 5.5 eV. Optionally, the bandgap width of the semiconductor layer 51 is 1.5 eV, 1.6 eV, 1.7 eV, 1.8 eV, 1.9 eV, 2.0 eV, 2.1 eV, 2.2 eV, 2.3 eV, 2.4 eV, 2.5 eV, 2.6 eV, 2.7 eV, 2.8 eV, 2.9 eV, 3.0 eV, 3.1 eV, 3.2 eV, 3.3 eV, 3 .4eV, 3.5eV, 3.6eV, 3.7eV, 3.8eV, 3.9eV, 4.0eV, 4.1eV, 4.2eV, 4.3eV, 4.4eV, 4.5eV, 4.6eV, 4.7eV, 4.8eV, 4.9eV, 5.0eV, 5.1eV, 5.2eV, 5.3eV, 5.4eV or 5.5eV.
[0038] In some embodiments, the resistance of the semiconductor layer 51 in the dark state is greater than or equal to 1% of the resistance of the insulating dielectric layer 41. When the resistance of the semiconductor layer 51 in the dark state is greater than or equal to 1% of the resistance of the insulating dielectric layer 41, the change in the resistance of the semiconductor layer 51 under shorter wavelength light irradiation can be more obvious than the resistance of the insulating dielectric layer 41, making the redistribution of the gate voltage more obvious, facilitating the distinction between the magnitude of the photocurrent and the dark current, and achieving higher feasibility of two-color detection. When the resistance of the semiconductor layer 51 in the dark state is too small compared to the insulating dielectric layer 41, the resistance change of the semiconductor layer 51 under lower wavelength photovoltaic irradiation is not obvious compared to the insulating dielectric layer 41. Optionally, the resistance of the semiconductor layer 51 in the dark state is 1%, 2%, 3%, 4%, 5%, 6%, 7%, 8%, 9%, 10%, 12%, 15%, 18%, 20%, 25%, 30%, 35%, 40%, 45%, 50%, 55%, 60%, 70%, 80%, 90% or 100% of the resistance of the insulating dielectric layer 41.
[0039] In some embodiments, the thickness of the semiconductor layer 51 is 20 nm to 1000 nm. The resistance of the semiconductor layer 51 of different materials in the dark state can be regulated by the thickness of the semiconductor layer 51. When the thickness of the semiconductor layer 51 is too large, the resistance of the semiconductor layer 51 in the dark state will be too small, resulting in too small a change in the resistance of the semiconductor layer 51 in the dark state and under the irradiation of light of a smaller wavelength; when the thickness of the semiconductor layer 51 is too small, the performance and reliability of the device may be reduced. Optionally, the thickness of the semiconductor layer 51 is 20nm, 21nm, 22nm, 23nm, 24nm, 25nm, 26nm, 27nm, 28nm, 29nm, 30nm, 32nm, 35nm, 40nm, 45nm, 50nm, 60nm, 70nm, 80nm, 100nm, 120nm, 150nm, 200nm, 250nm, 300nm, 350nm, 400nm, 450nm, 500nm, 550nm, 600nm, 650nm, 700nm, 750nm, 800nm, 850nm, 900nm, 950nm or 1000nm.
[0040] In some embodiments, the channel layer partially or completely covers the surface of the source electrode away from the substrate.
[0041] In some embodiments, the channel layer partially or entirely covers a surface of the drain electrode away from the substrate.
[0042] In some embodiments, the insulating dielectric layer partially or entirely covers the surface of the source electrode away from the substrate.
[0043] In some embodiments, the insulating dielectric layer partially or entirely covers the surface of the drain electrode away from the substrate.
[0044] In some embodiments, the insulating dielectric layer partially or entirely covers the surface of the substrate where the source electrode, the drain electrode, and the channel layer are not disposed.
[0045] In some embodiments, the material of the channel layer 31 is selected from at least one of silicon, molybdenum disulfide, tungsten disulfide, rhenium disulfide, tungsten diselenide, indium gallium zinc oxide (IGZO), gallium oxide, gallium arsenide, indium selenide, and organic semiconductors.
[0046] In some embodiments, the material of the semiconductor layer 51 is selected from at least one of silicon, molybdenum disulfide, tungsten disulfide, rhenium disulfide, tungsten diselenide, indium gallium zinc oxide, gallium oxide, gallium arsenide, indium selenide, and an organic semiconductor.
[0047] In some embodiments, the material of the insulating dielectric layer 41 is selected from at least one of silicon dioxide, silicon nitride, aluminum oxide, hafnium dioxide, titanium dioxide, polyethylene naphthalate, polyethylene terephthalate, polyimide, polymethyl methacrylate, polydimethylsiloxane, polyvinyl chloride, polycarbonate, polystyrene and polymethyl methacrylate.
[0048] In some embodiments, the source electrode 21 is selected from at least one of metal electrodes. Optionally, the source electrode 21 is a copper electrode, an aluminum electrode, a gold electrode, a silver electrode, a platinum electrode, a titanium electrode or a molybdenum electrode.
[0049] In some embodiments, the drain electrode 22 is selected from at least one of metal electrodes. Optionally, the drain electrode 22 is a copper electrode, an aluminum electrode, a gold electrode, a silver electrode, a platinum electrode, a titanium electrode or a molybdenum electrode.
[0050] In some embodiments, the gate electrode 61 is selected from at least one of metal electrodes. Optionally, the gate electrode 61 is a copper electrode, an aluminum electrode, a gold electrode, a silver electrode, a platinum electrode, a titanium electrode or a molybdenum electrode.
[0051] In some embodiments, the material of the substrate 11 is selected from at least one of silicon, silicon oxide, sapphire, glass, ceramic, polyethylene naphthalate, polyethylene terephthalate, polyimide, polymethyl methacrylate, polydimethylsiloxane, polyvinyl chloride, polycarbonate, polystyrene and polymethyl methacrylate.
[0052] In some embodiments, the insulating dielectric layer 41 also covers the surface of the source electrode 21 away from the substrate 11 .
[0053] In some embodiments, the insulating dielectric layer 41 also covers the surface of the drain electrode 22 away from the substrate 11 .
[0054] In some embodiments, the insulating dielectric layer 41 also covers a region of the surface of the substrate 11 where the source electrode 21 , the drain electrode 22 , and the channel layer 31 are not disposed.
[0055] Another embodiment of the present application also provides a method for preparing a phototransistor, including: providing a substrate 11; preparing a source electrode 21, a drain electrode 22 and a channel layer 31 on one surface of the substrate 11, respectively, the source electrode 21 and the drain electrode 22 are arranged at intervals, and the channel layer 31 is located between the source electrode 21 and the drain electrode 22 and is connected to the source electrode 21 and the drain electrode 22; preparing an insulating dielectric layer 41, a semiconductor layer 51 and a gate electrode 61 stacked in sequence on the surface of the channel layer 31 away from the substrate 11, and the band gap width of the semiconductor layer 51 is greater than the band gap width of the channel layer 31.
[0056] In some embodiments, the source electrode 21 is prepared by magnetron sputtering.
[0057] In some embodiments, patterning of source electrode 21 is achieved by photolithography.
[0058] In some embodiments, the drain electrode 22 is prepared by magnetron sputtering.
[0059] In some embodiments, patterning of drain electrode 22 is achieved by photolithography.
[0060] In some embodiments, the channel layer 31 is prepared by magnetron sputtering.
[0061] In some embodiments, patterning of the channel layer 31 is achieved by photolithography.
[0062] In some embodiments, the semiconductor layer 51 is prepared by magnetron sputtering.
[0063] In some embodiments, patterning of semiconductor layer 51 is achieved by photolithography.
[0064] In some embodiments, the insulating dielectric layer 41 is prepared by atomic layer deposition.
[0065] In some embodiments, the patterning of the insulating dielectric layer 41 is achieved by photolithography.
[0066] In some embodiments, the gate electrode 61 is prepared by magnetron sputtering.
[0067] In some embodiments, patterning of the gate electrode 61 is achieved by photolithography.
[0068] In some embodiments, before the source electrode 21 , the drain electrode 22 and the channel layer 31 are respectively prepared on the substrate 11 , the process further includes: cleaning the substrate 11 with acetone, alcohol and deionized water respectively.
[0069] In some embodiments, a method for preparing a phototransistor comprises the following steps:
[0070] (1) Providing a substrate 11;
[0071] (2) defining the patterns of the source electrode 21 and the drain electrode 22 on the surface of the substrate 11 by photoresist, preparing the source electrode 21 and the gate electrode 61 by magnetron sputtering, the source electrode 21 and the drain electrode 22 are spaced apart, and removing the resist;
[0072] (3) defining a pattern of the channel layer 31 on the surface of the substrate 11 by photoresist, preparing the channel layer 31 by magnetron sputtering, wherein the channel layer 31 is located between the source electrode 21 and the drain electrode 22 and is connected to the source electrode 21 and the drain electrode 22, and removing the resist;
[0073] (4) defining the pattern of the insulating dielectric layer 41 on the surface of the channel layer 31 away from the substrate 11 by photoresist, preparing the insulating dielectric layer 41 by atomic layer deposition, and removing the resist;
[0074] (5) defining the pattern of the semiconductor layer 51 on the surface of the insulating dielectric layer 41 away from the channel layer 31 by photoresist, preparing the semiconductor layer 51 by magnetron sputtering, wherein the band gap width of the semiconductor layer 51 is larger than the band gap width of the channel layer 31, and removing the resist;
[0075] (6) The pattern of the gate electrode 61 is defined by photoresist on the surface of the semiconductor layer 51 away from the insulating dielectric layer 41 , the gate electrode 61 is prepared by magnetron sputtering, and the resist is removed.
[0076] In one embodiment, the method for preparing the phototransistor comprises the following steps:
[0077] (1) Providing a substrate 11;
[0078] (2) defining the patterns of the source electrode 21 and the drain electrode 22 on the surface of the substrate 11 by photoresist, preparing the source electrode 21 and the gate electrode 61 by magnetron sputtering, the source electrode 21 and the drain electrode 22 are spaced apart, and removing the resist;
[0079] (3) defining a pattern of the channel layer 31 on the surface of the substrate 11 by photoresist, preparing the channel layer 31 by magnetron sputtering, wherein the channel layer 31 is located between the source electrode 21 and the drain electrode 22 and is connected to the source electrode 21 and the drain electrode 22, and removing the resist;
[0080] (4) defining the pattern of the insulating dielectric layer 41 on the surface of the channel layer 31 away from the substrate 11 by photoresist, preparing the insulating dielectric layer 41 by atomic layer deposition, and removing the resist;
[0081] (5) defining the pattern of the semiconductor layer 51 on the surface of the insulating dielectric layer 41 away from the channel layer 31 by photoresist, preparing the semiconductor layer 51 by magnetron sputtering, wherein the band gap width of the semiconductor layer 51 is larger than the band gap width of the channel layer 31, and removing the resist;
[0082] (6) The pattern of the gate electrode 61 is defined by photoresist on the surface of the semiconductor layer 51 away from the insulating dielectric layer 41 , the gate electrode 61 is prepared by magnetron sputtering, and the resist is removed.
[0083] Another embodiment of the present application further provides a photoelectric detection device, including any of the above-mentioned phototransistors or a phototransistor prepared by the above-mentioned method for preparing a phototransistor.
[0084] The following is a specific implementation method
[0085] Example 1
[0086] Refer again Figure 1 The phototransistor in this embodiment includes a substrate 11, a source electrode 21, a drain electrode 22, a channel layer 31, an insulating dielectric layer 41, a semiconductor layer 51 and a gate electrode 61. In this embodiment, the material of the substrate 11 is glass, the material of the source electrode 21 is Mo, the material of the drain electrode 22 is Mo, the material of the channel layer 31 is IGZO (band gap is 3.4 eV), the material of the insulating dielectric layer 41 is Al2O3, the material of the semiconductor layer 51 is Ga2O3 (band gap is 5 eV), and the material of the gate electrode 61 is Au. The source electrode 21 and the drain electrode 22 are arranged on the upper surface of the substrate 11 at intervals; the channel layer 31 is arranged on the surface of the substrate 11 and is located between the source electrode 21 and the drain electrode 22, the channel layer 31 is connected to the source electrode 21 and the drain electrode 22, the thickness of the channel layer 31 is greater than the source electrode 21 and the drain electrode 22, and the channel layer 31 partially covers the surface of the source electrode 21 and the drain electrode 22 away from the substrate 11. The insulating dielectric layer 41 is located on the surface of the channel layer 31 away from the substrate 11, and covers the surface of the source electrode 21 away from the substrate 11, the surface of the drain electrode 22 away from the substrate 11, and the surface of the substrate 11 not provided with the source electrode 21, the drain electrode 22, and the channel layer 31. The semiconductor layer 51 is provided on the surface of the insulating dielectric layer 41 away from the substrate 11, and the gate electrode 61 is provided on the surface of the conductor layer away from the substrate 11.
[0087] The preparation method of the phototransistor in this embodiment comprises the following steps:
[0088] (1) providing a glass substrate 11, and ultrasonically cleaning the glass substrate 11 in acetone, alcohol, and deionized water for 10 minutes each;
[0089] (2) defining the patterns of the source electrode 21 and the drain electrode 22 on the surface of the substrate 11 by photoresist, preparing the Mo source electrode 21 and the Mo gate electrode 61 by magnetron sputtering, the source electrode 21 and the drain electrode 22 are arranged at intervals, and removing the resist;
[0090] (3) defining the pattern of the channel layer 31 on the surface of the substrate 11 by photoresist, preparing the IGZO channel layer 31 by magnetron sputtering, the channel layer 31 being located between the Mo source electrode 21 and the Mo drain electrode 22 and connected to the source electrode 21 and the drain electrode 22, and removing the resist;
[0091] (4) defining the pattern of the Al2O3 insulating dielectric layer 41 on the surface of the IGZO channel layer 31 away from the glass substrate 11 by photoresist, preparing the Al2O3 insulating dielectric layer 41 by atomic layer deposition, and removing the resist;
[0092] (5) defining the pattern of the Ga2O3 semiconductor layer 51 on the surface of the Al2O3 insulating dielectric layer 41 away from the IGZO channel layer 31 by photoresist, preparing the Ga2O3 semiconductor layer 51 by magnetron sputtering, and removing the resist;
[0093] (6) On the surface of the Ga2O3 semiconductor layer 51 away from the Al2O3 insulating dielectric layer 41, a pattern of the Au gate electrode 61 is defined by photoresist, the Au gate electrode 61 is prepared by magnetron sputtering, and the resist is removed.
[0094] The phototransistor in Example 1 was subjected to a two-color recognition test. The gate voltage and drain voltage of the phototransistor were fixed at -3V and 1V, respectively, and the phototransistor was irradiated with light of 254nm and 365nm, respectively. Figure 3 , Figure 3 This is the response curve of the phototransistor to 254nm light. It can be seen that when the phototransistor is irradiated with 254nm wavelength light, the current is significantly reduced and the photocurrent is less than the dark current. Figure 4 , Figure 4 3 is the response curve of the phototransistor to 365nm light. It can be seen that when the phototransistor is irradiated with light of 365nm wavelength, the current increases significantly, and the photocurrent is greater than the dark current. That is, when the phototransistor in this embodiment is irradiated with light of 254nm or 365nm wavelength, the light of 254nm and 365nm wavelength can be identified and distinguished by comparing the size of the photocurrent and the dark current. The phototransistor in this embodiment can achieve dual-color recognition.
[0095] In this embodiment, the detection principle of the dual-color detection phototransistor is as follows: in the dark state, the equivalent circuit and gate voltage distribution of the semiconductor layer 51 and the insulating dielectric layer 41 are as follows: Figure 2 As shown, C 51 and R 51are the equivalent capacitance and resistance of the semiconductor layer 51, C 41 and R 41 are the equivalent capacitance and resistance of the insulating dielectric layer 41 respectively. The gate voltage is fixed to V GS , the gate voltage borne by the semiconductor layer 51 is V 51 , then the gate voltage borne by the insulating dielectric layer 41 is V 41 =V GS -V 51 , so the amount of electron charge depleted in the channel layer 31 is Q=C 41 ×(V GS -V 51 ). Under the irradiation of light with a shorter wavelength (i.e., matching the band gap of the semiconductor layer 51), the resistance of the semiconductor layer 51 decreases significantly. The resistance of the semiconductor layer 51 after the decrease is negligible compared with the resistance of the insulating dielectric layer 41. At this time, the gate voltage is almost entirely distributed on the insulating dielectric layer 41, i.e., V 41 =V GS , so the electron charge of the channel depletion is Q=C 41 ×V GS , at this time, the photocurrent will be lower than the dark current. Under the irradiation of light with a longer wavelength (i.e., matching the band gap of the channel layer 31), the resistance of the semiconductor layer 51 remains unchanged, so the relationship of the gate voltage distribution remains unchanged, and the channel layer 31 will generate carriers, resulting in a photocurrent higher than the dark current. By comparing the size of the photocurrent and the dark current, it is possible to distinguish between light of different wavelengths, that is, to achieve dual-color recognition.
[0096] The technical features of the above-described embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.
[0097] The above-mentioned embodiments only express several implementation methods of the present application, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the invention patent. It should be pointed out that, for a person of ordinary skill in the art, several variations and improvements can be made without departing from the concept of the present application, and these all belong to the protection scope of the present application. Therefore, the protection scope of the patent of the present application shall be subject to the attached claims, and the description and drawings may be used to interpret the contents of the claims.
Claims
1. A phototransistor, characterized in that: It includes a substrate, a source electrode, a drain electrode, a channel layer, an insulating dielectric layer, a semiconductor layer and a gate electrode; The source electrode and the drain electrode are arranged on a surface of the substrate at intervals; The channel layer is disposed on the surface of the substrate and is located between the source electrode and the drain electrode, and the channel layer is connected to the source electrode and the drain electrode; The insulating dielectric layer, the semiconductor layer and the gate electrode are sequentially stacked on a surface of the channel layer away from the substrate; The bandgap width of the semiconductor layer is greater than the bandgap width of the channel layer.
2. The phototransistor according to claim 1, characterized in that A difference between a band gap width of the semiconductor layer and a band gap width of the channel layer is greater than or equal to 0.2 eV.
3. The phototransistor according to claim 2, characterized in that The bandgap width of the channel layer is 0.2eV~5eV; And / or, the band gap width of the semiconductor layer is 1.5 eV~5.5 eV.
4. The phototransistor according to claim 1, characterized in that The resistance of the semiconductor layer in a dark state is greater than or equal to 1% of the resistance of the insulating dielectric layer.
5. The phototransistor according to claim 1, characterized in that The thickness of the semiconductor layer is 20nm~1000nm.
6. The phototransistor according to claim 1, wherein: The channel layer partially or entirely covers a surface of the source electrode away from the substrate; And / or, the channel layer partially or completely covers a surface of the drain electrode away from the substrate.
7. The phototransistor according to claim 1, wherein: The insulating dielectric layer partially or completely covers the surface of the source electrode away from the substrate; And / or, the insulating dielectric layer partially or completely covers the surface of the drain electrode away from the substrate; And / or, the insulating dielectric layer partially or completely covers the surface of the substrate where the source electrode, the drain electrode and the channel layer are not provided.
8. The phototransistor according to any one of claims 1 to 5, characterized in that: The material of the channel layer and the material of the semiconductor layer are each independently selected from at least one of silicon, molybdenum disulfide, tungsten disulfide, rhenium disulfide, tungsten diselenide, indium gallium zinc oxide, gallium oxide, gallium arsenide, indium selenide and an organic semiconductor; And / or, the material of the insulating dielectric layer is selected from at least one of silicon dioxide, silicon nitride, aluminum oxide, hafnium dioxide, titanium dioxide, polyethylene naphthalate, polyethylene terephthalate, polyimide, polymethyl methacrylate, polydimethylsiloxane, polyvinyl chloride, polycarbonate, polystyrene and polymethyl methacrylate; And / or, the source electrode, the drain electrode and the gate electrode are each independently selected from at least one of metal electrodes; And / or, the material of the substrate is selected from at least one of silicon, silicon oxide, sapphire, glass, ceramic, polyethylene naphthalate, polyethylene terephthalate, polyimide, polymethyl methacrylate, polydimethylsiloxane, polyvinyl chloride, polycarbonate, polystyrene and polymethyl methacrylate.
9. A method for preparing a phototransistor, characterized in that: include: providing a substrate; A source electrode, a drain electrode and a channel layer are respectively prepared on one surface of the substrate, wherein the source electrode and the drain electrode are arranged at intervals, and the channel layer is located between the source electrode and the drain electrode and is connected to the source electrode and the drain electrode; An insulating dielectric layer, a semiconductor layer and a gate electrode stacked in sequence are prepared on a surface of the channel layer away from the substrate, wherein the band gap width of the semiconductor layer is greater than the band gap width of the channel layer.
10. A photoelectric detection device, characterized in that: A phototransistor comprising the phototransistor according to any one of claims 1 to 8 or a phototransistor prepared by the method for preparing the phototransistor according to claim 9.