A non-visible light ultraviolet-infrared bipolar detector and its fabrication method

Abstract

This invention discloses a non-visible light ultraviolet-infrared bipolar detector and its fabrication method. The detector includes: a GaN epitaxial wafer, a ZnO:Ga microwire, a GaAs epitaxial wafer, a Ti / Au electrode, and a PDMS insulating layer. High-crystallinity ZnO:Ga microwires are grown by chemical vapor deposition and transferred to a GaAs epitaxial wafer coated with Ti / Au electrodes. PDMS films are attached to both sides of the ZnO:Ga microwires, and a double-polished GaN epitaxial wafer coated with Ti / Au electrodes is placed on top of the microwires. The double-polished GaN epitaxial wafer serves as a window for detecting polarized light, realizing a non-visible light bipolar detector based on a GaN / ZnO:Ga / GaAs heterojunction. Under zero bias conditions, when the device is irradiated with ultraviolet light, the generated current is positive; when the device is irradiated with infrared light, the generated current is negative; and when the device is irradiated with visible light, almost no current is generated. This invention provides a feasible solution for achieving a stable non-visible light ultraviolet-infrared bipolar detector through reasonable material and structural design.

Description

Technical Field

[0001] This invention belongs to the field of semiconductor optoelectronic device technology, specifically relating to the design and fabrication of a non-visible light bipolar detector. Background Technology

[0002] Photodetectors are one of the core components of photoelectric detection technology and play a vital role in the optoelectronic field. Among them, bipolar photodetectors have important and wide-ranging applications in many fields such as optical communication, smart chips, artificial neural network simulation, and optical computing. Although some bipolar photodetectors have been designed, they are typically based on materials such as perovskite, CdSe, and SnSe, thus exhibiting a significant photoresponse to visible light.

[0003] To date, no reports have been made of non-visible light bipolar photodetectors spanning the ultraviolet and infrared bands using semiconductor materials and structures. Therefore, from the perspective of developing multifunctional, integrable, and invisible optoelectronic micro / nano devices for the future, the fabrication of non-visible light ultraviolet-infrared bipolar photodetectors undoubtedly has significant scientific importance and research value.

[0004] This invention grows ZnO:Ga microwires using chemical vapor deposition and combines them with a double-polished GaN epitaxial wafer and a GaAs substrate to successfully achieve non-visible light-type ultraviolet-infrared bipolar photodetection. Summary of the Invention

[0005] The purpose of this invention is to address the shortcomings of the prior art by providing a non-visible ultraviolet-infrared bipolar detector based on GaN / ZnO:Ga / GaAs heterojunction and its fabrication method, thus providing a foundation and technical support for the construction of bipolar photodetectors.

[0006] The specific technical solution is as follows:

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

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

[0009] Preferably, the detectors adopt a bottom-up vertical stacking structure.

[0010] Preferably, the GaN epitaxial wafer is a double-polished type, p-type doped, with a doping concentration of 5 × 10⁻⁶. 15 ~5×10 16 cm -3 The migration rate is 200–500 cm. 2 / V·s.

[0011] Preferably, the GaAs substrate is p-type doped with a doping concentration of 1×10⁻⁶. 15 ~1×10 16 cm -3 The migration rate is 400–1000 cm. 2 / V·s.

[0012] Preferably, the diameter of the ZnO:Ga microwire ranges from 5 μm to 15 μm, and the doping concentration is 7 × 10⁻⁶. 17 ~3×10 18 cm -3 The migration rate is 10cm. 2 / V·s.

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

[0014] This invention also provides a method for fabricating a non-visible ultraviolet-infrared bipolar detector, comprising the following steps:

[0015] (1) ZnO:Ga microwires were grown using chemical vapor deposition.

[0016] (2) Clean and dry the GaN epitaxial wafer and GaAs substrate;

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

[0018] (4) Transfer the ZnO:Ga microwire to a GaAs substrate coated with Ti / Au metal electrodes, with one side in close contact with the GaAs substrate;

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

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

[0021] The method for growing ZnO:Ga microwires by chemical vapor deposition in step (1) is as follows: ZnO, Ga2O3, and C powders in a mass ratio of 12:1:13 are thoroughly mixed and ground, and placed in an alumina boat, with a small piece of Si substrate placed on top. The alumina boat is placed in a single-temperature tube furnace, heated to 1100℃ and held for 40 minutes, with a stable argon gas flow of 120 sccm. After removal and natural cooling, ZnO:Ga microwires can be obtained on the Si substrate.

[0022] The cleaning and drying method for the GaN epitaxial wafer and GaAs substrate described in step (2) is as follows: The GaN epitaxial wafer is placed in an acetone solution and ultrasonically cleaned for 15 minutes; the GaN epitaxial wafer is then removed from the acetone solution and ultrasonically cleaned in deionized water for 15 minutes using the same method. The GaN epitaxial wafer is then placed in an oven and dried for 1 hour, followed by drying with nitrogen gas. The GaAs substrate is cleaned and dried using the same method.

[0023] Step (3) involves depositing Ti / Au metal electrodes: a clean GaN epitaxial wafer is cut into 1.5cm x 5cm lengths and widths; using a mask and electron beam evaporation, a 1.5cm x 1cm layer of Ti metal with a thickness of 30nm to 50nm is first deposited on one side of the GaN epitaxial wafer; then a 1.5cm x 1cm layer of Au metal with a thickness of 100nm to 200nm is deposited on the Ti metal; the same method is used to deposit Ti / Au metal electrodes on the GaAs substrate.

[0024] Step (4) involves transferring the ZnO:Ga microwire to the GaAs substrate: A hexagonal ZnO:Ga microwire with a diameter of 10μm–20μm and a length of 5mm–1cm is removed from the silicon substrate using tweezers and placed horizontally on the GaAs substrate. The ZnO:Ga microwire is manipulated under an optical microscope, ensuring that one side of the ZnO:Ga microwire is in contact with the GaAs substrate. It is also ensured that the ZnO:Ga microwire does not contact the Ti / Au electrode of the GaAs.

[0025] In step (5), PDMS films are adhered to both sides of the GaAs on both sides of the ZnO:Ga microwire from step (4). The PDMS films do not contact the Ti / Au electrodes of the GaAs, nor do they contact the ZnO:Ga microwire. A GaN epitaxial wafer coated with Ti / Au metal electrodes is then placed on top of the ZnO:Ga microwire, ensuring complete adhesion between the GaN epitaxial wafer and 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 resulting device is then dried in a drying oven at 50–65°C for 30 minutes to obtain the detection device based on the 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 detector. The detector exhibits photoresponse in the ultraviolet and near-infrared bands, but almost no response to visible light, enabling non-visible ultraviolet and infrared light detection. Furthermore, the detector current is positive in the ultraviolet band but negative in the infrared band, exhibiting bipolar photoresponse characteristics.

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

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

[0029] Figure 2 This refers to the light response of the non-visible ultraviolet-infrared bipolar detector based on the GaN / ZnO:Ga / GaAs heterojunction in Embodiment 1 of the present invention in the infrared and ultraviolet bands.

[0030] Figure 3 The figure shows the spectral response of the non-visible ultraviolet-infrared bipolar detector based on the GaN / ZnO:Ga / GaAs heterojunction in Embodiment 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, and almost zero responsivity in the visible light range. Detailed Implementation

[0031] The present invention will be further described below with reference to the embodiments and accompanying drawings.

[0032] Example 1:

[0033] Step 1: Take 5g of ZnO, Ga2O3, and C powders in a mass ratio of 12:1:13, mix thoroughly, and grind using an agate mortar. Place the mixed powder into an alumina boat, and place a small piece of clean Si substrate on top. Place the alumina boat in the center of a single-zone tube furnace, introduce argon gas at 120 sccm as a protective gas, heat the furnace to 1100℃, and maintain this temperature for 40 minutes. After removing the alumina boat, allow it to cool naturally. ZnO:Ga microwires can be obtained on the Si substrate. The length of the microwires is 1mm to 1.5cm, and the diameter is 2μm to 30μm.

[0034] Step 2: Immerse the GaN epitaxial wafer in acetone solution and ultrasonically clean it for 15 minutes. Remove the GaN epitaxial wafer from the acetone solution, then immerse it in deionized water and ultrasonically clean it for 15 minutes. Place the GaN epitaxial wafer in an oven at 100°C and dry it for 1 hour. After drying, blow it dry with nitrogen gas. 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 x 5cm lengths and widths; using a mask and electron beam evaporation, first deposit a 1.5cm x 1cm layer of Ti metal with a thickness of 30nm on one side of the GaN epitaxial wafer; then deposit a 1.5cm x 1cm layer of Au metal with a thickness of 100nm on the Ti metal; using the same method, deposit a 1.5cm x 1cm Ti metal electrode with a thickness of 50nm on the GaAs substrate, and then deposit a 1.5cm x 1cm layer of Au metal with a thickness of 100nm on the Ti metal.

[0036] Step 4: Use tweezers to remove a hexagonal ZnO:Ga microwire with a diameter of 10 μm and a length of 5 mm from the silicon substrate. Place it horizontally on the GaAs substrate and manipulate 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 electrode of the GaAs.

[0037] Step 5: PDMS films are adhered to GaAs on both sides of the ZnO:Ga microwire. The PDMS films do not contact the Ti / Au electrodes of the GaAs, nor do they contact the ZnO:Ga microwire. A GaN epitaxial wafer coated with Ti / Au metal electrodes is then placed on top of the ZnO:Ga microwire, ensuring complete adhesion between the GaN epitaxial wafer and 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 resulting device is then dried in a drying oven at 50°C for 30 minutes, yielding a detection device based on a GaN / ZnO:Ga / GaAs heterojunction, such as... Figure 1 As shown.

[0038] Step 6: A 0V bias voltage was applied to the Ti / Au electrodes at both ends of the device, and then the photoresponse of the detector was tested. For example... Figure 2 As shown, the device exhibits near-infrared and ultraviolet light responses, enabling near-ultraviolet and infrared light detection.

[0039] Step 7: The spectral responsivity of the device was further tested. For example... Figure 3 As shown, the device exhibits a positive responsivity to ultraviolet light, a negative responsivity to infrared light, and almost no response to visible light. Therefore, a non-visible ultraviolet-infrared bipolar detection was successfully achieved based on the GaN / ZnO:Ga / GaAs heterojunction.

Claims

1. A non-visible light ultraviolet-infrared bipolar detector, characterized in that, The system comprises a GaN epitaxial wafer, ZnO:Ga microwires, a GaAs substrate, a PDMS thin film, and Ti / Au metal electrodes. The Ti / Au metal electrodes are deposited on the GaN epitaxial wafer and the GaAs substrate. The ZnO:Ga microwires are horizontally placed on the GaAs substrate. PDMS insulating layers are attached to both sides of the ZnO:Ga microwires. The GaN epitaxial wafer covers the top of the ZnO:Ga microwires. The GaN epitaxial wafer is double-polished. p Type doping; GaAs substrate is p Type doping.

2. The non-visible light ultraviolet-infrared bipolar detector according to claim 1, characterized in that, The ZnO:Ga microwires were prepared by chemical vapor deposition.

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

4. A non-visible ultraviolet-infrared bipolar detector according to claim 1, characterized in that, The doping concentration of the GaN epitaxial wafer is 5×10⁻⁶. 15 ~5×10 16 cm -3 The migration rate is 200~500 cm. 2 / V·s.

5. A non-visible ultraviolet-infrared bipolar detector according to claim 1, characterized in that, The doping concentration of the GaAs substrate is 1×10⁻⁶. 15 ~1×10 16 cm -3 The mobility is 400~1000 cm. 2 / V·s.

6. A non-visible ultraviolet-infrared bipolar detector according to claim 1, characterized in that, ZnO:Ga microwires have diameters ranging from 5 mm to 15 mm and doping concentrations of 7 × 10⁻⁶. 17 ~3×10 18 cm -3 The migration rate is 10 cm. 2 / V·s.

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

8. A method for preparing a non-visible ultraviolet-infrared bipolar detector according to any one of claims 1-7, characterized in that, Includes the following steps: (1) ZnO:Ga microwires were prepared by chemical vapor deposition. (2) Deposit Ti / Au metal electrodes on GaN epitaxial wafers and GaAs substrates respectively; (3) Transfer the ZnO:Ga microwire to a GaAs substrate coated with Ti / Au metal electrodes, with one side in close contact with the GaAs substrate; (4) PDMS films are attached to both sides of the ZnO:Ga microwire, and a GaN epitaxial wafer 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: ZnO, Ga2O3 and C powders with a mass ratio of 12:1:13 are thoroughly mixed and ground; the mixed powder is placed in an alumina boat, and a Si substrate is placed on top of the mixed powder; the alumina boat is placed in the central area of ​​a single-temperature zone tube furnace, argon gas of 120 sccm is introduced as a protective gas, the temperature of the tube furnace is heated to 1100 ℃ and maintained for 40 minutes; after the alumina boat is removed, it is allowed to cool naturally, and ZnO:Ga microwires are obtained on the Si substrate.

10. A non-visible light ultraviolet-infrared bipolar detection method, characterized in that, By applying a 0 V voltage across the Ti / Au metal electrode of the non-visible ultraviolet-infrared bipolar detector according to any one of claims 1-7, and using the GaN epitaxial wafer as the window for incident light, non-visible ultraviolet-infrared bipolar detection is achieved.

Images