Photoelectric detector based on non-noble metal plasmon and preparation method and use thereof

Abstract

The present invention relates to the field of photoelectric detection technology, in particular to a photoelectric detector based on non-noble metal plasmons and a preparation method thereof, as well as the use of the photoelectric detector. 3‑x Nanopowder is used as a surface plasmon material. After the nanopowder is pressed into a sheet, a patterned metal layer is evaporated on it. The metal layer is used as an electrode to obtain an array composed of many photodetectors. The metal layers in two adjacent metal area units and the conductive channels between them constitute a photodetector. The preparation process is simple and does not require the use of expensive equipment and time-consuming steps such as photolithography and electron beam etching. At an operating voltage as low as 10mV, the photodetector realizes photodetection in the near-infrared (NIR) spectral range, and the two-dimensional plane resolution of the detector array can reach 500 microns. The photodetector only uses lower-cost metal oxide surface plasmon materials, which significantly reduces material costs.

Description

Technical Field

[0001] The present invention relates to the field of optoelectronic detection technology, in particular to the synthesis of a non-metallic compound with surface plasmon effect, the preparation of an optoelectronic detector, and the performance test and verification. Background Art

[0002] At present, optoelectronic detectors are widely used in high-resolution imaging technology, optical wave communication, sensing and other fields. At present, common optoelectronic detectors are all designed based on semiconductors. For example, Ji Tao et al. (Chinese Patent, Patent Publication No.: CN110364583A) used TiO 2 thin flakes prepared by calcining ALD (atomic layer by layer deposition method) in an oxygen-containing environment, and the calcination temperature was 400-800 °C, that is, crystallized fish-scale-like TiO 2 thin flakes were prepared on the substrate. The source and drain of the field effect transistor were prepared on one side of the substrate containing TiO 2 thin flakes, the silicon oxide generated by calcination on the other side of the substrate was removed, and Au / Cr alloy, Au, Ag or Cu was plated as the gate to obtain the optoelectronic detection device. However, the wavelength of light responded by such optoelectronic detectors based on semiconductor materials is limited by the band gap of the semiconductor.

[0003] In recent years, people have begun to use the heterojunction of gold and silver noble metals and semiconductors to expand the response wavelength range. Noble metal nanostructures can generate surface plasmon effects in the visible light range, and then decay to generate hot electrons and hot holes, which can then be injected into the semiconductor, thereby improving the performance of the semiconductor and broadening the light response range. However, since gold and silver are metals with very good electrical conductivity, simply using gold and silver materials cannot generate optoelectronic responses. Summary of the Invention

[0004] The purpose of the present invention is to provide a preparation method of a broadband optoelectronic detector based on the plasmon effect of non-precious metals. The preparation method is simple and efficient, and the prepared optoelectronic detector realizes light detection in the wide spectral range of UV-Vis-NIR.

[0005] To achieve the above purpose, the present invention adopts the following technical solutions: A preparation method of an optoelectronic detector based on non-precious metal plasmons, comprising the following steps:

[0006] S1. Take MoO 3-x nanopowder containing oxygen vacancies, where the value range of x is 0 < x < 0.3, and this MoO 3-x presents a nanorod morphology, with an axial length of 2-5 μm and a radial width of 100-200 nm;

[0007] S2. Use a tablet press mold to press the MoO 3-x powder into a MoO with a thickness of 0.5-2 mm3-x Thin slices;

[0008] S3, in MoO 3-x A patterned metal area unit is set on the surface of the sheet, and then MoO 3-x The thin sheet is placed in a vacuum cavity, and a 50-100nm thick metal layer is evaporated in the area where the metal area unit is located to form a patterned metal layer. The material of the metal layer is one of Au, Ag, Al, and Ti. The patterned metal layer is used as an electrode to obtain a photodetector array. In the photodetector array, the metal layers on two adjacent metal area units and the conductive channels between the metal layers constitute a photodetector.

[0009] As a further improvement of the preparation method of photodetectors based on non-noble metal plasmons:

[0010] Preferably, the MoO containing oxygen vacancies 3-x Nanopowders were prepared by solvothermal or reduction methods on MoO 3 It is prepared by introducing oxygen vacancies into the powder.

[0011] Preferably, the reduction method is adding a strong reducing agent or high temperature reaction of hydrogen.

[0012] Preferably, the MoO containing oxygen vacancies 3-x The preparation method of the nano powder is as follows: high-purity molybdenum powder with a purity of more than 99.9wt% is thoroughly dissolved in hydrogen peroxide under stirring, and the dissolution amount of high-purity molybdenum powder in each liter of hydrogen peroxide is 0.6-0.9mol, and then isopropanol with a volume 4-9 times the volume of hydrogen peroxide is added, and stirring is continued for 20-60min to obtain a mixture, and the mixture is transferred to a polytetrafluoroethylene-lined autoclave, heated to 160-180°C and maintained for 8-16 hours, and the obtained powder is washed with ethanol and deionized water respectively, and then dried at a temperature of 40-80°C for 6-12 hours, and then placed in a hydrogen-argon mixed atmosphere with a flow rate of 60-100sccm, the volume ratio of hydrogen to argon in the mixed atmosphere is 1:9, and the mixture is heated at 5-10°C min -1 The MoO containing oxygen vacancies was obtained by heating the MoO to 350-470 °C at a heating rate of 100 °C and then heat treating at this temperature for 2-6 h. 3-x Nano powder.

[0013] Preferably, in step S2, a patterned metal region unit is provided by a mask plate process, and the specific steps are as follows: a metal mask provided with ordered through holes is taken, and the metal mask is closely attached to the MoO 3-x On the wafer, the through-hole portions on the metal mask constitute patterned metal area units.

[0014] Preferably, the metal region unit is rectangular in shape, has a size of 100-1000 μm, and a distance between centers of adjacent metal region units is 10-500 μm.

[0015] Preferably, the metal region unit is in a square shape with a size of 500 micrometers×500 micrometers.

[0016] A second object of the present invention is to provide a photoelectric detector based on non-noble metal plasmons obtained by the above-mentioned preparation method.

[0017] A third object of the present invention is to provide a use of the above-mentioned photodetector based on non-noble metal plasmons in near-infrared detection.

[0018] Compared with the prior art, the present invention has the following beneficial effects:

[0019] 1) The present invention provides a method for preparing a photodetector based on non-noble metal plasmons, comprising the following steps:

[0020] MoO with high concentration of oxygen vacancies 3-x Nanostructures are highly degenerate doped non-metallic compound semiconductor materials that can produce surface plasmon effects (usually in the near-infrared-infrared band). 3-x MoO can be prepared by reduction methods (strong reducing agents, hydrogen high temperature reaction, etc.) 3 It is prepared by introducing oxygen vacancies into the semiconductor.

[0021] Then, the obtained non-metallic compound with surface plasmon effect is pressed into a thin sheet by pressure. The size of the thin sheet can be achieved by adjusting the tablet pressing mold. 3-x A patterned metal area unit is set on the surface of the thin film, and a vacuum coating device is used to coat the pressed MoO 3-x A patterned metal layer is evaporated on the thin film as an electrode. The material of the metal layer is one of Au, Ag, Al, and Ti, and a photodetector is obtained, which realizes light response in the near-infrared spectrum. The preparation process of this method is simple, the preparation process is environmentally friendly, and the device has low energy consumption and low price. Because non-precious metal plasmon materials have larger reserves and are significantly cheaper than precious metals such as gold and silver, they have both semiconductor properties and surface plasmon effects equivalent to precious metal nanostructures, and are expected to be promoted and applied in the field of photoelectric detection.

[0022] 2) The process of preparing the photodetector of the present invention is simple, and does not require the use of expensive equipment and time-consuming steps such as photolithography and electron beam etching. The process is simple, low-cost and short-time. The photodetector prepared by the present invention is conducive to forming an array detector, which can realize light detection on a two-dimensional plane with a resolution of up to 500 microns. By further reducing the mask hole of the vapor-deposited electrode, a higher detector density and resolution can be obtained. The present invention uses a single non-metallic plasmon material MoO for the first time. 3-x The nanosheets construct photodetectors that have high photoresponse in the near-infrared spectral range. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 MoO prepared in Example 1 3-x SEM images, where (a) is a SEM image magnified 4000 times; (b) is a SEM image magnified 20000 times; (c) and (d) are SEM images of different positions of the sample magnified 40000 times, respectively.

[0024] Figure 2 The MoO formed by tableting in Example 1 3-x Optical photograph of thin film after vacuum evaporation of metal layer.

[0025] Figure 3 This is the photocurrent response of the device in Example 1 under 980nm monochromatic light illumination. DETAILED DESCRIPTION

[0026] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in the field without making creative work are within the scope of protection of the present invention.

[0027] Example 1

[0028] This embodiment provides a MoO with high concentration of oxygen vacancies. 3-x Powder and use of the MoO 3-x The method for preparing a detection device array from powder specifically comprises the following steps:

[0029] 1) Preparation of MoO containing oxygen vacancies 3-xNanopowder: Dissolve 0.72g of high-purity molybdenum powder (>99.9%) thoroughly in hydrogen peroxide under magnetic stirring, dissolve in 5mL of hydrogen peroxide, then add isopropanol 6 times the volume of hydrogen peroxide to the solution and continue stirring for 40 minutes. Transfer the mixture to a stainless steel autoclave lined with polytetrafluoroethylene, heat to 170°C in a drying oven, and keep for 12 hours. The resulting powder was washed 3 times with ethanol and deionized water, respectively. Then, the obtained powder was dried at 60°C for 12 hours. Finally, it was placed in a mixed atmosphere (10% H2, 90% Ar) at 60sccm and heated at 5°C min -1 The MoO with oxygen vacancies was obtained by heat treatment at 370 °C for 4 h. 3-x Nano powder, 0 <x<0.3;

[0030] 2) The obtained MoO 3-x The powder (0.42 g) was pressed into a circular sheet with a thickness of 1 mm and a diameter of 10 mm;

[0031] 3) On the surface of the thin film, a patterned metal area unit is set by a mask plate process, and a through hole array is set on the mask plate. The through holes are 500 microns × 500 microns squares, and the repetition period is 600×550μm, that is, in the plane direction of the thin film, the center distances of adjacent metal area units are 550μm and 600μm respectively, and then the thin film covered by the mask is placed in a vacuum chamber, and a 70nm metal layer is evaporated on the set patterned metal area unit by electron beam evaporation, and the metal is Au. The thin film is taken out, the mask plate is removed, and the patterned metal layer formed on the thin film is used as an electrode to obtain a photodetector array.

[0032] The MoO prepared in step 1) was examined using a field emission scanning electron microscope. 3-x Scan, the result is as follows Figure 1 As shown, (a) is a SEM image magnified 4000 times; (b) is a SEM image magnified 20000 times; (c) and (d) are SEM images of different positions of the sample magnified 40000 times; the MoO 3-x It has a nanorod morphology, with an axial length of 2-5 μm and a radial width of 100-200 nm.

[0033] The device wafer after the metal electrode deposition obtained in step 2) was photographed using a camera and an electron scanning microscope. The results are as follows: Figure 2As shown in the figure, the optical photo is shown in (a) and the SEM image is shown in (b). The diameter in step 2 can be adjusted over a wide range by changing the diameter of the mold. The larger the area, the larger the number of detector arrays that can be obtained. Obviously, the resolution of the detector array is directly related to the hole size of the mask plate of the evaporated electrode. A smaller hole diameter will result in a higher density detector array. Compared with the need for micromachining platforms and technologies to prepare microelectrodes, this method is simpler and less costly.

[0034] The performance of photoelectric detection devices is tested using a semiconductor parameter analyzer. Figure 3 The surface plasmon MoO 3-x The photocurrent response of the photodetector prepared by the nanosheet under 980nm monochromatic light irradiation, the power is 100mW, and the operating voltage applied to all samples is 0.01V. At an operating voltage as low as 10mV, photodetection in the near-infrared (NIR) spectral range is achieved, and the two-dimensional plane resolution can reach 500 microns. Its working mechanism is that MoO 3-x When the nanosheet is exposed to light, LSPR absorption occurs, which then decays to produce plasmon hot electrons and hot holes. Under an external bias, the hot electrons and hot holes migrate in opposite directions, forming an increased photocurrent. It can be seen that the working principle of this sensor is significantly different from previous semiconductor sensors and photoelectric sensors based on metal / semiconductor heterojunctions.

[0035] Example 2

[0036] This embodiment provides a MoO with high concentration of oxygen vacancies. 3-x Powder and use of the MoO 3-x The method for preparing a detection device array from powder specifically comprises the following steps:

[0037] 1) Preparation of MoO containing oxygen vacancies 3-x Nanopowder: Dissolve 0.5 g of high-purity molybdenum powder (>99.9%) thoroughly in hydrogen peroxide under magnetic stirring, dissolve in 4 mL of hydrogen peroxide, then add isopropanol 7 times the volume of hydrogen peroxide to the solution and continue stirring for 50 minutes. Transfer the mixture to a stainless steel autoclave lined with polytetrafluoroethylene, heat to 160°C in a drying oven, and keep for 15 hours. The resulting powder was washed 3 times with ethanol and deionized water, respectively. Then, the obtained powder was dried at 80°C for 12 hours. Finally, it was placed in a mixed atmosphere (10% H2, 90% Ar) at 70 sccm and heated at 8°C min -1 The MoO with oxygen vacancies was obtained by heat treatment at 370 °C for 4 h. 3-x Nano powder, 0 <x<0.3;

[0038] 2) The obtained MoO 3-x The powder (0.63 g) was pressed into round sheets with a thickness of 1.5 mm and a diameter of 10 mm;

[0039] 3) On the surface of the thin film, a patterned metal area unit is set by a mask plate process, and a through-hole array is set on the mask plate. The through-holes are 500 microns × 500 microns squares, and the repetition period is 600 × 550 μm, that is, in the plane direction of the thin film, the center distances of adjacent metal area units are 550 μm and 600 μm respectively, and then the thin film covered by the mask is placed in a vacuum chamber, and a 90nm metal layer is evaporated on the set patterned metal area unit by electron beam evaporation, and the metal is Au. The thin film is taken out, the mask plate is removed, and the patterned metal layer formed on the thin film is used as an electrode to obtain a photodetector array.

[0040] Prepared MoO 3-x The material was tested by scanning electron microscopy and the structure was similar to that of Example 1.

[0041] Surface plasmon MoO 3-x The photocurrent response of the photodetector prepared by the nanosheets under 980nm monochromatic light irradiation, the power is 100mW, and the operating voltage applied to all samples is 0.01V. At an operating voltage as low as 10mV, photodetection in the near-infrared (NIR) spectral range is achieved, and the two-dimensional plane resolution can reach 500 microns.

[0042] Example 3

[0043] This embodiment provides a MoO with high concentration of oxygen vacancies. 3-x Powder and use of the MoO 3-x The method for preparing a detection device array from powder specifically comprises the following steps:

[0044] 1) Preparation of MoO containing oxygen vacancies 3-x Nanopowder: Dissolve 0.9 g of high-purity molybdenum powder (>99.9%) thoroughly in hydrogen peroxide under magnetic stirring, dissolve in 8 mL of hydrogen peroxide, then add isopropanol 8 times the volume of hydrogen peroxide to the solution and continue stirring for 60 minutes. Transfer the mixture to a stainless steel autoclave lined with polytetrafluoroethylene, heat to 170°C in a drying oven, and keep for 16 hours. The resulting powder was washed 3 times with ethanol and deionized water, respectively. Then, the obtained powder was dried at 50°C for 12 hours. Finally, it was placed in a mixed atmosphere (10% H2, 90% Ar) at 100 sccm and heated at 10°C min -1 The MoO with oxygen vacancies was obtained by heat treatment at 370 °C for 6 h. 3-x Nano powder, 0 <x<0.3;

[0045] 2) The obtained MoO 3-x The powder (0.84 g) was pressed into a circular sheet with a thickness of 2 mm and a diameter of 10 mm;

[0046] 3) On the surface of the thin film, a patterned metal area unit is set by a mask plate process, and a through-hole array is set on the mask plate. The through-holes are 500 microns × 500 microns squares, and the repetition period is 600×550μm, that is, in the plane direction of the thin film, the center distances of adjacent metal area units are 550μm and 600μm respectively, and then the thin film covered by the mask is placed in a vacuum chamber, and a 100nm metal layer is evaporated on the set patterned metal area unit by electron beam evaporation, and the metal is Au. The thin film is taken out, the mask plate is removed, and the patterned metal layer formed on the thin film is used as an electrode to obtain a photodetector array.

[0047] Prepared MoO 3-x The material was tested by scanning electron microscopy and the structure was similar to that of Example 1.

[0048] Surface plasmon MoO 3-x The photocurrent response of the photodetector prepared by the nanosheets under 980nm monochromatic light irradiation, the power is 100mW, and the operating voltage applied to all samples is 0.01V. At an operating voltage as low as 10mV, photodetection in the near-infrared (NIR) spectral range is achieved, and the two-dimensional plane resolution can reach 500 microns.

[0049] Those skilled in the art should understand that the above are only some specific embodiments of the present invention, rather than all embodiments. It should be noted that for those of ordinary skill in the art, many modifications and improvements can be made, and all modifications or improvements that do not exceed the scope of protection of the present invention should be regarded as the scope of protection of the present invention.

Claims

1. A method for preparing a photodetector based on non-noble metal plasmons, characterized in that: The steps include: S1. Take MoO with oxygen vacancies 3-x nano powder, where the value range of x is 0 < x < 0.3, and this MoO 3-x shows a nanorod morphology, with an axial length of 2 - 5 μm and a radial width of 100 - 200 nm; S2, use a tableting mold to 3-x The powder is pressed into MoO with a thickness of 0.5-2 mm. 3-x Thin slices; S3, in MoO 3-x A patterned metal area unit is set on the surface of the sheet, and then MoO 3-x The thin sheet is placed in a vacuum cavity, and a 50-100nm thick metal layer is evaporated in the area where the metal area unit is located to form a patterned metal layer. The material of the metal layer is one of Au, Ag, Al, and Ti. The patterned metal layer is used as an electrode to obtain a photodetector array. In the photodetector array, the metal layers on two adjacent metal area units and the conductive channels between the metal layers constitute a photodetector.

2. The method for preparing a photodetector based on non-noble metal plasmons according to claim 1, characterized in that: The MoO containing oxygen vacancies 3-x The nanopowders were prepared by introducing oxygen vacancies into MoO3 powders via a solvothermal method or a reduction method.

3. The method for preparing a photodetector based on non-noble metal plasmons according to claim 2, characterized in that: The reduction method is to add a strong reducing agent or hydrogen high temperature reaction.

4. The method for preparing a photodetector based on non-noble metal plasmons according to claim 2, characterized in that: The MoO containing oxygen vacancies 3-x The preparation method of the nano powder is as follows: high-purity molybdenum powder with a purity of more than 99.9wt% is thoroughly dissolved in hydrogen peroxide under stirring, and the dissolution amount of high-purity molybdenum powder in each liter of hydrogen peroxide is 0.6-0.9mol, and then isopropanol with a volume 4-9 times the volume of hydrogen peroxide is added, and stirring is continued for 20-60min to obtain a mixture, and the mixture is transferred to a polytetrafluoroethylene-lined autoclave, heated to 160-180°C and maintained for 8-16 hours, and the obtained powder is washed with ethanol and deionized water respectively, and then dried at a temperature of 40-80°C for 6-12 hours, and then placed in a hydrogen-argon mixed atmosphere with a flow rate of 60-100sccm, the volume ratio of hydrogen to argon in the mixed atmosphere is 1:9, and the mixture is heated at 5-10°C min -1 The MoO containing oxygen vacancies was obtained by heating the MoO to 350-470 °C at a heating rate of 100 °C and then heat treating at this temperature for 2-6 h. 3-x Nano powder.

5. The method for preparing a photodetector based on non-noble metal plasmons according to claim 1, characterized in that: In step S2, a patterned metal region unit is set by a mask plate process. The specific steps are as follows: a metal mask with ordered through holes is taken, and the metal mask is placed close to the MoO 3-x On the wafer, the through-hole portions on the metal mask constitute patterned metal area units.

6. The method for preparing a photodetector based on non-noble metal plasmons according to claim 1, characterized in that: The metal region unit is rectangular in shape, has a size of 100-1000 μm, and the closest distance between adjacent metal region units is 10-500 μm.

7. The method for preparing a photodetector based on non-noble metal plasmons according to claim 6, characterized in that: The metal region unit is in a square shape with a size of 500 micrometers×500 micrometers.

8. A photodetector based on non-noble metal plasmons prepared by the preparation method according to any one of claims 1 to 7.

9. Use of the non-noble metal plasmon-based photodetector according to claim 8 in near-infrared detection.

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