Invisible light type ultraviolet and infrared bipolar detector and preparation method thereof

Abstract

The invention discloses an invisible light type ultraviolet and infrared bipolar detector and a preparation method thereof. The detector comprises a GaN epitaxial wafer, a ZnO: Ga micron wire, a GaAs epitaxial wafer, a Ti / Au electrode and a PDMS insulating layer. The method comprises the following steps: growing a ZnO: Ga micron wire with high crystal quality through a chemical vapor deposition method, and transferring the ZnO: Ga micron wire to a GaAs epitaxial wafer plated with a Ti / Au electrode; pDMS films are attached to the two sides of the ZnO: Ga microwire, and the top end of the ZnO: Ga microwire is covered with a double-polished GaN epitaxial wafer plated with a Ti / Au electrode. And the double-polished GaN epitaxial wafer is used as a window for detecting polarized light, so that the invisible light type bipolar detector based on the GaN / ZnO: Ga / GaAs heterojunction is realized. Under the condition of zero bias voltage, when the device is irradiated by ultraviolet light, the generated current is positive; when the device is irradiated by infrared light, the generated current is negative; when the device is irradiated by visible light, almost no current is generated. Through reasonable material and structural design, a feasible scheme is provided for realizing a stable invisible light type ultraviolet and infrared bipolar detector.

Description

Technical Field

[0001] The invention belongs to the technical field of semiconductor optoelectronic devices, and in particular relates to the design and preparation of a non-visible light bipolar detector. Background Art

[0002] Photodetector components are one of the core components of photodetection technology and play a very important role in the optoelectronic field. Among them, bipolar photodetectors have important and extensive applications in many fields such as optical communications, smart chips, artificial neural simulation, and optical computing. Although some bipolar photodetectors have been designed, they are usually designed based on materials such as perovskite, CdSe, and SnSe, so the device has a significant light response to visible light.

[0003] So far, there has been no report on the use of semiconductor materials and structures to realize non-visible light bipolar photodetectors that span the ultraviolet and infrared bands. Therefore, from the perspective of future multifunctional, integrable, and invisible optoelectronic micro-nano devices, the preparation of non-visible light ultraviolet-infrared bipolar detectors undoubtedly has important scientific significance and research value.

[0004] The present invention grows ZnO:Ga micrometer wires by chemical vapor deposition method, combines double-polished GaN epitaxial wafers and GaAs substrates, and successfully realizes non-visible light type ultraviolet infrared bipolar light detection. Summary of the invention

[0005] The purpose of the present invention is to address the deficiencies of the above-mentioned prior art and provide a non-visible light ultraviolet infrared bipolar detector based on GaN / ZnO:Ga / GaAs heterojunction and a preparation method thereof, so as to provide a basis and technical support for constructing a bipolar photoelectric detector.

[0006] The specific technical solutions are as follows:

[0007] To achieve the above purpose, the non-visible light ultraviolet infrared bipolar detector based on GaN / ZnO:Ga / GaAs heterojunction of the present invention comprises a GaN epitaxial wafer, a ZnO:Ga micron wire, a GaAs substrate, a PDMS insulating layer, and a Ti / Au metal electrode; the Ti / Au electrode is evaporated on the GaN epitaxial wafer and the GaAs substrate; the ZnO:Ga micron wire is horizontally placed on the GaAs substrate; the PDMS insulating layer is attached to both sides of the ZnO:Ga micron wire; and the GaN epitaxial wafer covers the top of the ZnO:Ga micron wire.

[0008] Preferably, the ZnO:Ga microwires are prepared by chemical vapor deposition.

[0009] Preferably, the detector adopts a vertical stacking structure from bottom to top.

[0010] Preferably, the GaN epitaxial wafer is double-throw type, p-type doped, and the doping concentration is 5×10 15 ~5×10 16 cm -3 , mobility is 200~500cm 2 / V·s.

[0011] Preferably, the GaAs substrate is p-type doped with a doping concentration of 1×10 15 ~1×10 16 cm -3 , mobility is 400~1000cm 2 / V·s.

[0012] Preferably, the diameter of the ZnO:Ga microwires ranges from 5 μm to 15 μm, and the doping concentration is 7×10 17 ~3×10 18 cm -3 , the mobility is 10cm 2 / V·s.

[0013] Preferably, in the Ti / Au electrode, the thickness of Ti is 20 nm to 60 nm, and the thickness of Au is 80 nm to 120 nm.

[0014] The present invention also provides a method for preparing a non-visible light ultraviolet infrared bipolar detector, comprising the following steps:

[0015] (1) Growing ZnO:Ga microwires using chemical vapor deposition;

[0016] (2) Cleaning and drying the GaN epitaxial wafer and GaAs substrate;

[0017] (3) Using a mask to evaporate Ti / Au metal electrodes on the double-polished GaN epitaxial wafer and GaAs substrate respectively;

[0018] (4) transferring the ZnO:Ga microwires onto a GaAs substrate coated with a Ti / Au metal electrode, with one side of the ZnO:Ga microwires being closely attached to the GaAs substrate;

[0019] (5) PDMS films are attached to both sides of the ZnO:Ga microwires, and a GaN epitaxial wafer coated with Ti / Au metal electrodes is covered on the top of the ZnO:Ga microwires;

[0020] (6) A voltage of 0 V is applied to both ends of the device electrodes prepared in step (5), and the double-polished GaN epitaxial wafer is used as a window for incident light. The prepared device can realize non-visible light ultraviolet infrared bipolar detection.

[0021] Step (1) The method of growing ZnO:Ga micron wires by chemical vapor deposition: ZnO, Ga2O3 and C powders with a mass ratio of 12:1:13 are fully mixed and ground, and placed in a corundum boat, with a small Si substrate placed on top. The corundum boat is placed in a single-temperature tube furnace, the growth temperature is heated to 1100°C and maintained for 40 minutes, and 120sccm of stable argon is passed through. After being taken out and cooled naturally, ZnO:Ga micron wires can be obtained on the Si substrate.

[0022] Step (2) The cleaning and drying method of the GaN epitaxial wafer and the GaAs substrate is as follows: the GaN epitaxial wafer is placed in an acetone solution and ultrasonically cleaned for 15 minutes; the GaN epitaxial wafer is taken out of the acetone solution, and the GaN epitaxial wafer is ultrasonically cleaned for 15 minutes in deionized water using the same method; the GaN epitaxial wafer is placed in an oven and dried for 1 hour, and then blown dry with nitrogen. The GaAs substrate is cleaned and dried using the same method.

[0023] Step (3) of evaporating Ti / Au metal electrodes: cutting a clean GaN epitaxial wafer into a length and width of 1.5 cm×5 cm; using a mask and electron beam evaporation, first evaporating 1.5 cm×1 cm of Ti metal on one side of the GaN epitaxial wafer with a thickness of 30 nm to 50 nm; then evaporating 1.5 cm×1 cm of Au metal on the Ti metal with a thickness of 100 nm to 200 nm; using the same method to evaporate Ti / Au metal electrodes on a GaAs substrate.

[0024] Step (4) The preparation of transferring the ZnO:Ga microwire to the GaAs substrate: Using tweezers, take out a ZnO:Ga microwire with a hexagonal cross section from the silicon substrate, with a diameter of 10 μm to 20 μm and a length of 5 mm to 1 cm, and place it horizontally on the GaAs substrate. Operate the ZnO:Ga microwire under an optical microscope to ensure that one side of the ZnO:Ga microwire is in contact with the GaAs substrate. Also, ensure that the ZnO:Ga microwire does not contact the Ti / Au electrode of the GaAs.

[0025] In step (5), PDMS films are respectively adhered to the GaAs on both sides of the ZnO:Ga microwire in step (4), and the PDMS films do not contact the Ti / Au electrodes of GaAs or the ZnO:Ga microwire. A GaN epitaxial wafer coated with a Ti / Au metal electrode is covered on the top of the ZnO:Ga microwire to ensure that the GaN epitaxial wafer is completely attached to the top of the ZnO:Ga microwire and the ZnO:Ga microwire does not contact the Ti / Au electrodes of the GaN epitaxial wafer. The obtained device is placed in a drying cabinet for drying at a temperature of 50 to 65°C for 30 minutes to obtain a detection device based on a GaN / ZnO:Ga / GaAs heterojunction.

[0026] In step (6), a 0V voltage is applied to the Ti / Au electrodes at both ends of the GaN / ZnO:Ga / GaAs heterojunction detection device. The detection device exhibits light response in the ultraviolet band and near-infrared band, but has almost no response to visible light, and can realize non-visible light ultraviolet infrared light detection. In addition, the detector current is positive in the ultraviolet band, but negative in the infrared band, showing a bipolar light response characteristic.

[0027] The beneficial effects of the present invention are as follows: the present invention uses a double-throw GaN epitaxial wafer as a window for detecting polarized light, and realizes a non-visible light bipolar detector based on a GaN / ZnO:Ga / GaAs heterojunction. Under zero bias conditions, when the device is irradiated by ultraviolet light, the current generated is positive; when the device is irradiated by infrared light, the current generated is negative; when the device is irradiated by visible light, almost no current is generated. The invention provides a feasible solution for realizing a stable non-visible light ultraviolet infrared bipolar detector through reasonable material and structural design. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 This is a schematic diagram of the non-visible light ultraviolet infrared bipolar detector based on GaN / ZnO:Ga / GaAs heterojunction of the present invention. (1.GaN epitaxial wafer, 2.GaAs substrate, 3.ZnO:Ga microwire, 4.PDMS film, 5.Ti / Au)

[0029] Figure 2 It is the light response of the non-visible light ultraviolet infrared bipolar detector based on GaN / ZnO:Ga / GaAs heterojunction in Example 1 of the present invention in the infrared band and the ultraviolet band.

[0030] Figure 3 The spectral response of the non-visible light ultraviolet infrared bipolar detector based on GaN / ZnO:Ga / GaAs heterojunction in Example 1 of the present invention. As can be seen from the figure, the device has a positive responsivity in the ultraviolet band, a negative responsivity in the infrared band, but a responsivity of almost zero in the visible light range. DETAILED DESCRIPTION

[0031] The present invention will be further described below in conjunction with the embodiments and drawings.

[0032] Embodiment 1:

[0033] Step 1: Take 5g of ZnO, Ga2O3 and C powders with a mass ratio of 12:1:13, mix them thoroughly, and grind them with an agate mortar. Put the mixed powder into a corundum boat, and place a small clean Si substrate on top. Put the corundum boat into the center area of ​​a single-temperature zone tube furnace, introduce 120sccm of argon as a protective gas, heat the tube furnace to 1100℃, and keep it for 40 minutes. After taking out the corundum boat, cool it naturally, and ZnO:Ga microwires can be obtained on the Si substrate. The length of the microwire is 1mm~1.5cm and the diameter is 2μm~30μm.

[0034] Step 2: Place the GaN epitaxial wafer in an acetone solution and perform ultrasonic cleaning for 15 minutes; remove the GaN epitaxial wafer from the acetone solution, and then place the GaN epitaxial wafer in deionized water for ultrasonic cleaning for 15 minutes, place the GaN epitaxial wafer in an oven at 100°C, dry it for 1 hour, and then blow it dry with nitrogen. Use the same method and steps to clean and dry the GaAs substrate.

[0035] Step 3: Cut the clean GaN epitaxial wafer into 1.5cm×5cm in length and width; use a mask and electron beam evaporation to first evaporate 1.5cm×1cm of Ti metal with a thickness of 30nm on one side of the GaN epitaxial wafer; then evaporate 1.5cm×1cm of Au metal with a thickness of 100nm on the Ti metal; use the same method to evaporate a 1.5cm×1cm Ti metal electrode with a thickness of 50nm on the GaAs substrate, and then evaporate 1.5cm×1cm of Au metal with a thickness of 100nm on the Ti metal.

[0036] Step 4: Use tweezers to take out a ZnO:Ga microwire with a hexagonal cross-section, a diameter of 10μm, and a length of 5mm from the silicon substrate, and place it horizontally on the GaAs substrate. Operate the ZnO:Ga microwire under an optical microscope to ensure that one side of the ZnO:Ga microwire is completely in contact with the GaAs substrate and that the ZnO:Ga microwire does not contact the Ti / Au electrodes of the GaAs.

[0037] Step 5: PDMS films are adhered to the GaAs on both sides of the ZnO:Ga microwire. The PDMS films do not contact the Ti / Au electrodes of GaAs or the ZnO:Ga microwire. Cover the top of the ZnO:Ga microwire with a GaN epitaxial wafer coated with Ti / Au metal electrodes to ensure that the GaN epitaxial wafer is completely in contact with the top of the ZnO:Ga microwire and that the ZnO:Ga microwire does not contact the Ti / Au electrodes of the GaN epitaxial wafer. The obtained device is placed in a drying cabinet for drying at 50°C for 30 minutes to obtain a detection device based on the GaN / ZnO:Ga / GaAs heterojunction, such as Figure 1 shown.

[0038] Step 6: Apply a 0V bias voltage to the Ti / Au electrodes at both ends of the device, and then perform a light response test on the detection device. Figure 2 As shown, the device exhibits near-infrared light response and ultraviolet light response, and can realize near-ultraviolet light and infrared light detection.

[0039] Step 7: Further test the spectral responsivity of the device. Figure 3 As shown in the figure, the device shows positive responsivity to ultraviolet light, negative responsivity to infrared light, and almost no response to visible light. Therefore, non-visible light ultraviolet infrared bipolar detection is successfully realized based on GaN / ZnO:Ga / GaAs heterojunction.

Claims

1. A non-visible light ultraviolet infrared bipolar detector, characterized in that: It includes GaN epitaxial wafer, ZnO:Ga micron wire, GaAs substrate, PDMS film, Ti / Au metal electrode; Ti / Au metal electrode is evaporated on GaN epitaxial wafer and GaAs substrate; ZnO:Ga micron wire is horizontally placed on GaAs substrate; PDMS insulating layer is attached to both sides of ZnO:Ga micron wire; GaN epitaxial wafer covers the top of ZnO:Ga micron wire.

2. The non-visible light ultraviolet infrared bipolar detector according to claim 1, characterized in that: The ZnO:Ga micrometer wire is prepared by a chemical vapor deposition method.

3. The non-visible light ultraviolet infrared bipolar detector according to claim 1, characterized in that: Adopt a bottom-up vertical stacking structure.

4. The non-visible light ultraviolet infrared bipolar detector according to claim 1, characterized in that: The GaN epitaxial wafer is double-throw type, p-type doped, and the doping concentration is 5×10 15 ~5×10 16 cm -3 , mobility is 200~500cm 2 / V·s.

5. The non-visible light ultraviolet infrared bipolar detector according to claim 1, characterized in that: The GaAs substrate is p-type doped with a doping concentration of 1×10 15 ~1×10 16 cm -3 , mobility is 400~1000cm 2 / V·s.

6. The non-visible light ultraviolet infrared bipolar detector according to claim 1, characterized in that: The diameter of ZnO:Ga microwires ranges from 5μm to 15μm, and the doping concentration is 7×10 17 ~3×10 18 cm -3 , the mobility is 10cm 2 / V·s.

7. The non-visible light ultraviolet infrared bipolar detector according to claim 1, characterized in that: The thickness of Ti in the Ti / Au metal electrode is 20nm to 60nm, and the thickness of Au is 80nm to 120nm.

8. The method for preparing a non-visible light ultraviolet infrared bipolar detector according to any one of claims 1 to 7, characterized in that: The steps include: (1) Preparation of ZnO:Ga microwires by chemical vapor deposition; (2) Evaporating Ti / Au metal electrodes on GaN epitaxial wafers and GaAs substrates respectively; (3) transferring the ZnO:Ga microwires onto a GaAs substrate coated with a Ti / Au metal electrode, with one side of the ZnO:Ga microwires being closely attached to the GaAs substrate; (4) A PDMS film is attached to both sides of the ZnO:Ga microwire, and a GaN epitaxial wafer coated with Ti / Au metal electrodes is covered on the top of the ZnO:Ga microwire.

9. The preparation method according to claim 8, characterized in that: The chemical vapor deposition method in step (1) is as follows: fully mix and grind ZnO, Ga2O3 and C powders with a mass ratio of 12:1:13; put the mixed powder into a corundum boat, and place a Si substrate on the mixed powder; put the corundum boat into the central area of ​​a single-temperature zone tubular furnace, introduce 120sccm of argon as a protective gas, heat the temperature of the tubular furnace to 1100°C, and maintain it for 40 minutes; after taking out the corundum boat, cool it naturally to obtain ZnO:Ga micrometer wires on the Si substrate.

10. A non-visible light ultraviolet infrared bipolar detection method, characterized in that: A 0V voltage is applied to both ends of the Ti / Au metal electrodes of the non-visible light ultraviolet infrared bipolar detector described in any one of claims 1-7, and the GaN epitaxial wafer is used as a window for incident light to achieve non-visible light ultraviolet infrared bipolar detection.

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