A silicon carbide nano hollow column array and a solar-blind ultraviolet detector based thereon

Abstract

The present invention discloses a silicon carbide nano hollow column array and a solar-blind ultraviolet detector based thereon. The silicon carbide nano hollow column array is made by a two-step maskless inductively coupled plasma etching method. The structure of the detector is as follows: the upper surface of the silicon carbide substrate is etched into a silicon carbide nano hollow column array, and Ti3C2T x The thin film and the Ti3AlC2 thin film serve as Schottky contact electrodes and ohmic contact electrodes respectively. The detector prepared by the invention has the advantages of high-quality Schottky characteristics, high-performance solar-blind ultraviolet response, and easy preparation of large-area devices.

Description

Technical Field

[0001] The present invention belongs to the technical field of semiconductor optoelectronic devices, and in particular relates to a silicon carbide nano hollow column array and a solar-blind ultraviolet detector based thereon. Background Art

[0002] Silicon carbide (SiC) is widely used to construct ultraviolet (UV) photodetectors due to its wide bandgap (~3.2eV), excellent thermal conductivity and outstanding radiation resistance. These outstanding properties enable silicon carbide-based UV photodetectors to be used in chemically inert, high-temperature and strong radiation environments. In recent years, with the significant progress in silicon carbide semiconductor epitaxial growth technology and processing technology, silicon carbide UV photodetectors have been widely used in small-area devices (≤5mm 2) has achieved high responsiveness, low dark current and excellent visible light blind response characteristics (References: [1] S. Liang, Y. Dai, G. Wang, H. Xia, and J. Zhao,"Room-temperature fabrication of SiC microwire photodetectors on rigid and flexible substrates via femtosecond laser direct writing," Nanoscale, vol. 12, no. 45, pp. 23200-23205, Nov. 2020, doi: 10.1039 / d0nr05299j. [2] L. DiBenedetto, G. D. Licciardo, T. Erlbacher, A. J. Bauer, and A. Rubino,"A 4H-SiC UVphototransistor with excellent optical gain based on controlled potential barrier," IEEE Trans. Electron Devices, vol.67, no.1, pp.154-159, Jan.2020, doi:10.1109 / ted.2019.2950986.[3]L.Li,D.Zhou,H.Lu,W.Liu,X.Mo,F.Ren,D.Chen,R.Wang,G.Li,R.Zhang,and Y.Zheng,"4H-SiC avalanche photodiode linear array operating in geiger mode," IEEE Photon.J., vol.9, no.5, pp.1-7, Oct.2017, doi:10.1109 / jphot.2017.2750686.).However, due to the special applications in gas or pollution monitoring and spectroscopic instruments, the fabrication of large-area SiC UV photodiodes with high sensitivity has received active attention and remains a challenge (Reference: [4] A. Sciuto, G. Giudice, G. D'Arrigo, A. Meli, L. Calcagno, S. Di Franco, M. Mazzillo, G. Franzo, S. Albergo, A. Tricomi, and D. Longo, "Large-area SiC-UV photodiode forspectroscopy portable system," IEEE Sens. J., vol. 19, no. 8, pp. 2931-2936, Apr. 2019, doi: 10.1109 / jsen.2019.2891833.). Currently, people generally try to improve the quantum efficiency of these photodetectors by reducing the reflectivity and improving the effective optical coupling with the incident light. Among these structures, micro / nano-pillar or hole arrays are attractive for building large-area photodetectors because they can be fabricated using inductively coupled plasma (ICP) technology. ICP etching is one of the most important processes in the fabrication of these pillar or hole arrays. Therefore, by exploring the process parameters of ICP etching, it is expected that the desired silicon carbide nano-pillar or hole arrays can be produced. Summary of the Invention

[0003] In view of the shortcomings of the above-mentioned prior art, the present invention aims to provide a silicon carbide nano-hollow column array and a solar-blind ultraviolet detector based thereon. The technical problem to be solved is: first, by exploring the process parameters of ICP etching, a silicon carbide nano-hollow column array structure is obtained, and then by setting up a silicon carbide-based device structure, a solar-blind ultraviolet photoelectric detector with the advantages of solar-blind ultraviolet response, fast response speed, and easy integration is obtained.

[0004] In order to solve the technical problem, the present invention adopts the following technical solution:

[0005] The present invention firstly discloses a method for preparing a silicon carbide hollow nano-pillar array, which is characterized in that: in a maskless environment, the upper surface of the silicon carbide substrate is subjected to ICP etching to form a silicon carbide hollow nano-pillar array structure.

[0006] Furthermore, the ICP etching is carried out in two steps, and the process conditions of each step are:

[0007] The first step of etching: the vacuum chamber pressure is 5×10 -3The gas flow rates of Pa and SF6 are 60 sccm, the gas flow rate of O2 is 20 sccm, the ICP source power is 400 W, the bias source power is 80 W, and the etching time is 20-35 min.

[0008] The second step of etching: the vacuum chamber pressure is 5×10 -3 The gas flow rates of Pa and SF6 are 15 sccm, the gas flow rate of O2 is 15 sccm, the ICP source power is 200 W, the bias source power is 100 W, and the etching time is 10-25 min.

[0009] Furthermore, the thickness of the silicon carbide substrate used is 350 μm, and the diameter of the obtained silicon carbide hollow nanocolumn array is 100-400 nm and the height is 700-1000 nm.

[0010] The present invention also discloses a solar-blind ultraviolet detector based on the above-mentioned silicon carbide nano-hollow column array, which has the following structure: an N-type silicon carbide substrate is used as a base, a silicon carbide nano-hollow column array is formed on the upper surface of the silicon carbide substrate by ICP etching; Ti3C2T3 as a top electrode is spin-coated on the silicon carbide nano-hollow column array. x A Ti3AlC2 film is deposited on the lower surface of the silicon carbide substrate; a bottom electrode is provided on the lower surface of the Ti3AlC2 film; wherein the Ti3C2T x The film forms a Schottky junction with the silicon carbide hollow nanometer column array, and the Ti3AlC2 film forms an ohmic contact with the silicon carbide substrate.

[0011] Furthermore, the Ti3AlC2 film is prepared by pulsed laser deposition (PLD) technology and has a thickness of 20-100 nm.

[0012] Furthermore, the Ti3C2T x The film is a single layer or multilayer MXene, prepared by surface spin coating, with a thickness of 200-800nm.

[0013] Furthermore, the bottom electrode is an In / Ga electrode with a thickness of 20-100 nm.

[0014] Compared with the prior art, the beneficial effects of the present invention are embodied in:

[0015] 1. The present invention has produced a silicon carbide nano-hollow column array structure with uniform size by exploring the process parameters of ICP etching. When used to construct ultraviolet detection devices, this structure exhibits a good light trapping effect and a good light capture effect.

[0016] 2. In the ultraviolet detector constructed by the present invention, the silicon carbide nano hollow column array and Ti3C2T xThe thin film forms a Schottky contact, while the silicon carbide substrate and the Ti3AlC2 thin film form an ohmic contact. Ultraviolet light is amplified, and thanks to the Schottky heterojunction, rapid and efficient detection of ultraviolet light is achieved. Simultaneously, by manipulating the size of the hollow columns on the silicon carbide surface and utilizing the light trapping effect, the irradiated light undergoes multiple reflections and refractions within the holes, improving the device's quantum efficiency.

[0017] 3. The present invention uses Ti3AlC2 film as the ohmic contact electrode, which can obtain good ohmic contact on the lightly doped n-SiC substrate, avoiding the high-temperature annealing process of traditional metal contact. At the same time, good ohmic contact behavior is also a necessary prerequisite for the development of high-performance SiC-based photodetectors.

[0018] 4. The present invention uses Ti3C2T x MXene film as Schottky contact electrode has high conductivity and transparency, and its surface has no dangling bonds, which is beneficial to reduce the dark current during photodetection. x MXene has different electronegativity elements (fluorine, oxygen, chlorine) and functional groups (-OH-FO-Cl) in the Tx group, which give it an effective work function that matches the photodetector structure of the present invention.

[0019] 5. The device structure of the present invention can realize the manufacture of large-area silicon carbide ultraviolet photodetectors with high sensitivity.

[0020] 6. The detector prepared by the present invention has the advantages of day-blind ultraviolet detection, fast response speed, and easy integration. It also has the advantages of simple preparation method, low cost, and high stability. It has broad application prospects in low-power, high-current, high-sensitivity, and high-gain ultraviolet detection systems. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 Schematic diagram of the structure of the planar silicon carbide-based solar-blind ultraviolet detector prepared in Comparative Example 1;

[0022] Figure 2 Schematic diagram of the structure of the solar-blind ultraviolet detector based on the silicon carbide hollow nanorod array prepared in Example 1;

[0023] Figure 3 AFM image of the Ti3AlC2 film prepared in Example 1;

[0024] Figure 4 is the SEM image, where Figure 4 (a) is a SEM image of the silicon carbide hollow nanorod array etched by ICP maskless etching in Example 1. Figure 4 (b) is the SEM image of the height of the nano hollow pillar array;

[0025] Figure 5 The Ti3C2T3 is spin-coated on the silicon carbide hollow nanorod array in Example 1. x SEM images of thin films;

[0026] Figure 6 Ti3C2T prepared in Example 1 x XRD patterns of thin films;

[0027] Figure 7 Ti3C2T prepared in Example 1 x Raman spectroscopy of thin films;

[0028] Figure 8 It is the IV curve of Ti3AlC2-SiC-Ti3AlC2 structure;

[0029] Figure 9 The IV curve of the solar-blind ultraviolet detector based on the silicon carbide hollow nanorod array prepared in Example 1 in a dark environment from -2V to +2V;

[0030] Figure 10 The device normalized 1 / C of the solar-blind ultraviolet detector based on the silicon carbide hollow nanorod array prepared in Example 1 at a frequency of 1 MHz is: 2 -V curve;

[0031] Figure 11 At 0.25mW / cm 2 Under the same light intensity, the IV curves of the solar-blind ultraviolet detector based on the silicon carbide nano hollow pillar array prepared in Example 1 under different wavelengths of light;

[0032] Figure 12 The relevant responsivity (R) and external quantum efficiency (EQE) curves of the solar-blind ultraviolet detector based on the silicon carbide hollow nanorod array prepared in Example 1 under irradiation of light of different wavelengths;

[0033] Figure 13 The solar-blind ultraviolet detector based on silicon carbide hollow nanorod array prepared in Example 1 (Ti3C2T x / SiC NCHs) and the solar-blind ultraviolet detector based on planar silicon carbide prepared in Comparative Example 1 (Ti3C2T x / planar SiC), a comparison of the responsivity under different wavelengths calculated at a bias voltage of -1V;

[0034] Figure 14 The response curve of the solar-blind ultraviolet detector based on the silicon carbide hollow nanorod array prepared in Example 1 at different light intensities under zero bias voltage and 254nm light changes over time;

[0035] Figure 15 Comparison of the responsivity and effective area of ​​the solar-blind ultraviolet detector based on the silicon carbide hollow nanorod array prepared in Example 1 with those of previously reported silicon carbide-based photodiodes;

[0036] Figure 16 The graphs are of hollow nanorod arrays of different areas prepared under different etching time conditions in each embodiment and the corresponding device responsivity;

[0037] Figure 17 The surface of the silicon carbide hollow nanorod array prepared in Example 1 was spin-coated with Ti3C2T x The film is spin-coated with Ti3C2T on the planar silicon carbide surface in Comparative Example 1. x UV absorption curve of the film;

[0038] Figure 18 This is the light intensity distribution image of the solar-blind ultraviolet detector based on the silicon carbide nano-hollow pillar array in Example 1 obtained by Slivaco TCAD 3D simulation under 254nm illumination conditions;

[0039] Figure 19 The electric field distributions of the solar-blind ultraviolet detector based on the silicon carbide nano-hollow pillar array in Example 1 and the solar-blind ultraviolet detector based on the planar silicon carbide in Comparative Example 1 under different illumination conditions obtained by finite-difference time-domain simulation;

[0040] Number in the figure: 1 is Ti3C2T x film; 2 is a silicon carbide hollow nanocolumn array; 3 is a silicon carbide substrate; 4 is a Ti3AlC2 film; 5 is a bottom electrode. DETAILED DESCRIPTION

[0041] The following is a detailed description of an embodiment of the present invention. This embodiment is implemented based on the technical solution of the present invention, and provides a detailed implementation method and specific operation process. However, the protection scope of the present invention is not limited to the following embodiment.

[0042] Comparative Example

[0043] like Figure 1 As shown, this comparative example provides a solar-blind ultraviolet detector based on planar silicon carbide, which uses an N-type silicon carbide substrate 3 as a base, and a Ti3C2T3O4 layer as a top electrode is spin-coated on the N-type silicon carbide substrate. x Film 1; a Ti3AlC2 film 4 is deposited on the lower surface of the silicon carbide substrate 3; a bottom electrode 5 is provided on the lower surface of the Ti3AlC2 film; wherein, Ti3C2T x The film forms a Schottky junction with the silicon carbide substrate, and the Ti3AlC2 film forms an ohmic contact with the silicon carbide substrate.

[0044] The preparation method of the planar silicon carbide-based solar-blind ultraviolet detector of this comparative example comprises the following steps:

[0045] a. Soak a 10*11mm, 350μm thick silicon carbide substrate in a 20% HF solution for 2 minutes to remove the surface oxide layer. Then, rinse it in acetone, ethanol, and deionized water for 5 minutes in sequence to remove organic matter on the surface.

[0046] b. A Ti3AlC2 thin film was deposited on the lower surface of the silicon carbide substrate by pulsed laser deposition. The process conditions were: laser power 150 mJ, pulse frequency 3 Hz, gas pressure 1 × 10 -3 Pa, the vacuum chamber temperature is 500℃, and the deposition time is 30min.

[0047] c. Spin-coat a layer of Ti3C2T on the upper surface of silicon carbide x film.

[0048] d. Coat an In / Ga electrode on the Ti3AlC2 film as the bottom electrode, completing the preparation of the day-blind ultraviolet detector based on planar silicon carbide.

[0049] Example 1

[0050] like Figure 2 As shown, this embodiment provides a solar-blind ultraviolet detector based on a silicon carbide nano-hollow column array. The N-type silicon carbide substrate 3 is used as a base. A silicon carbide nano-hollow column array 2 is formed on the upper surface of the silicon carbide substrate by ICP etching. Ti3C2T3 is spin-coated on the silicon carbide nano-hollow column array 2 as a top electrode. x Film 1; a Ti3AlC2 film 4 is deposited on the lower surface of the silicon carbide substrate 3; a bottom electrode 5 is provided on the lower surface of the Ti3AlC2 film; wherein, Ti3C2T x The film forms a Schottky junction with the silicon carbide nano hollow column array, and the Ti3AlC2 film forms an ohmic contact with the silicon carbide substrate 3.

[0051] The method for preparing a solar-blind ultraviolet detector based on a silicon carbide hollow nanorod array in this embodiment includes the following steps:

[0052] a. Soak a 10*11mm, 350μm thick silicon carbide substrate in a 20% HF solution for 2 minutes to remove the surface oxide layer. Then, rinse it in acetone, ethanol, and deionized water for 5 minutes in sequence to remove organic matter on the surface.

[0053] b. In a maskless environment, ICP etching is performed on the upper surface of the silicon carbide substrate to form a silicon carbide hollow nano-pillar array structure. The ICP etching is carried out in two steps: the first step is a strong etching with high power and high flow rate, and the second step is a weak etching with low power and low flow rate. The second weak etching can remove the surface contaminants left by the first strong etching. The process conditions for each step are:

[0054] The first step of etching: the vacuum chamber pressure is 5×10 -3 The gas flow rates of Pa and SF6 are 60 sccm, the gas flow rate of O2 is 20 sccm, the ICP source power is 400 W, the bias source power is 80 W, and the etching time is 35 min.

[0055] The second step of etching: the vacuum chamber pressure is 5×10 -3 The gas flow rates of Pa and SF6 are 15 sccm, the gas flow rate of O2 is 15 sccm, the ICP source power is 200 W, the bias source power is 100 W, and the etching time is 25 min.

[0056] c. A Ti3AlC2 thin film was deposited on the lower surface of the silicon carbide substrate by pulsed laser deposition. The process conditions were: laser power 150 mJ, pulse frequency 3 Hz, gas pressure 1 × 10 -3 Pa, the vacuum chamber temperature is 500℃, and the deposition time is 30min.

[0057] d. Place the etched silicon carbide substrate on the suction cup of the clean coating machine, turn on the vacuum adsorption to fix it, and spin-coat a layer of Ti3C2T on its upper surface at a low speed. x The film is then transferred to the silicon carbide substrate and heated on a glue baking table, and dried under the condition of keeping the temperature not exceeding 40°C.

[0058] e. Coating an In / Ga electrode on the Ti3AlC2 film as the bottom electrode completes the preparation of a solar-blind ultraviolet detector based on a silicon carbide nanohollow column array.

[0059] Figure 3 This is an AFM image of the Ti3AlC2 film, which shows the high uniformity of the film and its surface roughness is ~5nm.

[0060] Figure 4 is the SEM image, where Figure 4 (a) is a SEM image of the silicon carbide hollow nanorod array etched by ICP maskless etching in this embodiment. Figure 4(b) shows an SEM image of the height of the hollow nanopillar array. The diameter of the hollow nanopillar array is ~200 nm, and the height ranges from 800 to 910 nm. These results demonstrate that ICP maskless etching can produce silicon carbide hollow nanopillar array structures with uniform size and morphology.

[0061] Figure 5 Ti3C2T is spin-coated on the silicon carbide hollow nanorod array. x The SEM image of the film shows that the nano hollow column array etched on the silicon carbide surface is covered by Ti3C2T x The film covers very well.

[0062] Figure 6 、 Figure 7 Ti3C2T x The XRD characterization images and Raman spectroscopy images of the film are consistent with previous reports, proving that it forms high-quality Ti3C2T x film.

[0063] Figure 8 This is the current-voltage (IV) curve of Ti3AlC2-SiC-Ti3AlC2. The results show that the use of PLD-Ti3AlC2 electrode on the surface can obtain good ohmic contact on the lightly doped n-SiC substrate, avoiding the high-temperature annealing process of traditional metal contact. At the same time, good ohmic contact behavior is also a necessary prerequisite for the development of high-performance SiC-based photodetectors.

[0064] Figure 9 The IV curve of the solar-blind ultraviolet detector based on the silicon carbide nano hollow pillar array prepared in Example 1 is from -2V to +2V in a dark environment. The test results show that the device has a high resistance of up to 1.04×10 3 Excellent rectification ratio.

[0065] Figure 10 The 1 / C of the solar-blind ultraviolet detector based on the silicon carbide hollow nanorod array prepared in Example 1 is 2 -V curve, the built-in potential on the semiconductor side is calculated to be 1.03eV. Furthermore, the device's barrier height can be calculated based on relevant formulas to be 1.46eV. This barrier height is higher than that of most previous silicon carbide-based Schottky barrier diodes that use traditional metals as Schottky contact electrodes, facilitating the separation of photogenerated carriers.

[0066] Figure 11 At 0.25mW / cm 2Under the same light intensity, the IV curves of the day-blind ultraviolet detector based on the silicon carbide nano hollow column array prepared in Example 1 under light of different wavelengths can be clearly seen from the measurement results that the prepared day-blind ultraviolet detector has obvious light-sensitive response characteristics to ultraviolet light, but has no obvious light response to light greater than or equal to 405nm, which indicates that the device has day-blind-ultraviolet response characteristics.

[0067] Figure 12 The responsivity (R) and external quantum efficiency (EQE) curves of the solar-blind ultraviolet detector based on the silicon carbide nanohollow column array prepared in Example 1 under different wavelengths of irradiation are calculated at a bias voltage of -1V. The peak responsivity reaches 327.5mA / W at 254nm, corresponding to an EQE of 160%.

[0068] Figure 13 The solar-blind ultraviolet detector based on silicon carbide hollow nanorod array prepared in Example 1 (Ti3C2T x / SiC NCHs) and the solar-blind ultraviolet detector based on planar silicon carbide prepared in Comparative Example 1 (Ti3C2T x / planar SiC), a comparison curve of the responsivity under different wavelengths of irradiation calculated under the condition of a bias voltage of -1V. The results clearly show that the responsivity of the detector with the nano hollow pillar array structure prepared in this embodiment is about 4 times that of the detector with a planar structure at a peak value of 254nm.

[0069] Figure 14 The response curve of the solar-blind ultraviolet detector based on the silicon carbide nano-hollow pillar array prepared in Example 1 at zero bias voltage and 254nm light with different light intensities changes over time. From the measurement results, it can be seen that the device has a stable current switching ratio of up to 10 4 , which demonstrates that the device has the capability of a self-powered photodiode.

[0070] Figure 15 Comparison of the responsivity and effective area of ​​the solar-blind UV detector based on the silicon carbide hollow nanopillar array prepared in Example 1 with previously reported silicon carbide-based photodiodes. It can be clearly seen that the photodiode of the present invention exhibits higher responsivity and larger effective area than metal / SiC and graphene (Gr) / SiC Schottky photodiodes and even some silicon carbide avalanche photodiodes (SiC APDs), indicating that the work of the present invention has opened up a new path for the preparation of large-area silicon carbide Schottky photodiodes for high-responsivity UV photodetectors.

[0071] In summary, the solar-blind ultraviolet detector based on the silicon carbide hollow nanocolumn array prepared in this embodiment has an obvious high-speed and stable response in the solar-blind-ultraviolet light band.

[0072] Example 2

[0073] The solar-blind ultraviolet detector based on the silicon carbide hollow nanocolumn array provided in this embodiment is basically the same in structure and preparation method as that of Example 1, with the only difference being that the etching time of the two-step maskless ICP etching in step b of Example 1 is changed to 30 minutes and 20 minutes respectively.

[0074] Example 3

[0075] The solar-blind ultraviolet detector based on the silicon carbide nano-hollow column array provided in this embodiment is basically the same in structure and preparation method as that of Example 1, with the only difference being that the etching time of the two-step maskless ICP etching in step b of Example 1 is changed to 25 minutes and 15 minutes respectively.

[0076] Example 4

[0077] The solar-blind ultraviolet detector based on silicon carbide nano-hollow column array provided in this embodiment is basically the same as that in Example 1 in structure and preparation method, with the only difference being that the etching time of the two-step maskless ICP etching in step b of Example 1 is changed to 20 minutes and 10 minutes respectively.

[0078] like Figure 16 As shown, according to the research of the present invention, the effective pillar area of ​​the nano hollow pillar arrays prepared under different etching time conditions in Examples 1, 2, 3, and 4 is also different. Within a certain etching time range, a larger effective pillar area is beneficial to improving the responsiveness of the device.

[0079] Figure 17 The surface of the silicon carbide hollow nanorod array prepared in Example 1 was spin-coated with Ti3C2T x The film is spin-coated with Ti3C2T on the planar silicon carbide surface in Comparative Example 1. x The UV absorption curve of the film shows that the significant enhancement of this responsiveness can be attributed to the improvement of light absorption.

[0080] Figure 18 The light intensity distribution image of the day-blind ultraviolet detector based on the silicon carbide nano-hollow column array obtained in Example 1 of the three-dimensional TCAD simulation near the Schottky junction under 254nm illumination conditions can be seen. It can be seen that the closer to the junction, the greater the light intensity, and the light intensity gradually weakens with increasing depth, indicating that the nano-hollow column array structure has a good light trapping effect.

[0081] like Figure 19To further explore this mechanism, finite-difference time-domain simulations were used to simulate the electric field distributions of the solar-blind UV detector based on the silicon carbide hollow nanopillar array prepared in Example 1 and the solar-blind UV detector based on planar silicon carbide prepared in the comparative example under different illumination conditions. The results showed that the solar-blind UV detector based on the silicon carbide hollow nanopillar array had a stronger electric field distribution, particularly under 254nm illumination. Therefore, the silicon carbide hollow nanopillar array has a significant light-harvesting effect, which can be attributed to the high responsivity of the van der Waals Schottky photodiode.

[0082] In summary, the present invention is the first to prepare a large-area silicon carbide nano-hollow column array with light-trapping effect by ICP maskless etching, and use it to prepare Ti3C2T x / Silicon carbide nano hollow column array van der Waals Schottky photodiode, for the first time combined PLD-Ti3AlC2 film and Ti3C2T x MXene serves as both the ohmic and Schottky contact electrodes. The device exhibits visible-blind UV response, with a peak responsivity of 320 mA / W at a bias voltage of -1 V under 254 nm illumination. This is significantly higher than most currently available silicon carbide-based UV photodiodes, opening up a new path for the fabrication of large-area silicon carbide Schottky photodiodes for high-responsivity UV photodetectors.

[0083] The above description is merely an exemplary embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention shall be included in the scope of protection of the present invention.

Claims

1. A solar-blind ultraviolet detector based on a silicon carbide hollow nanorod array, characterized by: An N-type silicon carbide substrate (3) is used as a base, and a silicon carbide nano-hollow column array (2) is formed on the upper surface of the silicon carbide substrate by ICP etching in a maskless environment; Ti3C2T3 as a top electrode is spin-coated on the silicon carbide nano-hollow column array (2). x A Ti3AlC2 film (4) is deposited on the lower surface of the silicon carbide substrate (3); a bottom electrode (5) is provided on the lower surface of the Ti3AlC2 film; wherein the Ti3C2T x The film forms a Schottky junction with the silicon carbide nano hollow column array, and the Ti3AlC2 film forms an ohmic contact with the silicon carbide substrate (3); The ICP etching is carried out in two steps, and the process conditions of each step are: The first step of etching: the vacuum chamber pressure is 5×10 -3 The gas flow rates of Pa and SF6 were 60 sccm, the gas flow rate of O2 was 20 sccm, the ICP source power was 400 W, the bias source power was 80 W, and the etching time was 20-35 min; The second step of etching: the vacuum chamber pressure is 5×10 -3 The gas flow rates of Pa and SF6 are 15 sccm, the gas flow rate of O2 is 15 sccm, the ICP source power is 200 W, the bias source power is 100 W, and the etching time is 10-25 min.

2. The solar-blind ultraviolet detector according to claim 1, characterized in that: The diameter of the silicon carbide hollow nanocolumn array is 100-400 nm and the height is 700-1000 nm.

3. The solar-blind ultraviolet detector according to claim 1, wherein: The Ti3AlC2 film is prepared by pulsed laser deposition technology and has a thickness of 20-100 nm.

4. The solar-blind ultraviolet detector according to claim 1, wherein: The Ti3C2T x The film is a single layer or multilayer MXene, prepared by surface spin coating, with a thickness of 200-800 nm.

5. The solar-blind ultraviolet detector according to claim 1, wherein: The bottom electrode (5) is an In / Ga electrode with a thickness of 20-100 nm.

Images