Silicon-based thermal photovoltaic cell and preparation method thereof

Abstract

The present invention discloses a silicon-based thermophotovoltaic cell and a preparation method thereof, wherein the silicon-based thermophotovoltaic cell comprises: a silicon substrate; an N-type GaSb film on the silicon substrate; a cascade thermophotovoltaic cell on the N-type GaSb film, wherein the cascade thermophotovoltaic cell comprises a plurality of thermophotovoltaic cell units stacked in layers; a P-type GaSb film on the cascade thermophotovoltaic cell; and electrodes, comprising a first electrode on the P-type GaSb film and a second electrode on the N-type GaSb film. By introducing the cascade thermophotovoltaic cell, the present invention can effectively absorb photons, ensure quantum efficiency and be simple to prepare, effectively overcome the shortcomings of traditional thermophotovoltaic cells, and can realize mass production and large-scale application; at the same time, the use of a silicon substrate can greatly reduce the production cost, which is conducive to market application.

Description

Technical Field

[0001] The invention belongs to the field of semiconductor technology, and in particular relates to a silicon-based thermal photovoltaic cell and a preparation method thereof. Background Art

[0002] Air pollution and greenhouse effect have become serious environmental problems facing the world, and the key solution is to reduce the consumption of fossil fuels that cause greater environmental pollution and to improve energy utilization and reduce waste. Thermophotovoltaic (TPV) technology has attracted much attention for its energy saving and environmental protection. Compared with traditional photovoltaic cells, thermophotovoltaic cells mainly absorb infrared wavelengths, so in principle, as long as there is heat, it can be used to generate electricity, which makes it of great significance in the development of new energy and industrial waste heat recovery.

[0003] After years of research, it was found that using indium arsenide or gallium antimonide as substrate materials can effectively realize TPV technology. However, the structure of infrared thermal photovoltaic cells grown based on indium arsenide or gallium antimonide as substrate materials is relatively expensive. At the same time, the traditional absorption region is difficult to prepare using a PIN structure, and the absorption region is thicker and cannot achieve a high absorption efficiency, thus reducing the practicality of TPV technology.

[0004] Therefore, in view of the above technical problems, it is necessary to provide a silicon-based thermal photovoltaic cell and a preparation method thereof. Summary of the invention

[0005] In view of this, an object of the present invention is to provide a silicon-based thermal photovoltaic cell and a preparation method thereof, so as to solve the problems of high cost and low absorption efficiency of the infrared thermal photovoltaic cell structure on a gallium antimonide substrate.

[0006] In order to achieve the above purpose, the technical solution provided by an embodiment of the present invention is as follows:

[0007] A silicon-based thermal photovoltaic cell, comprising:

[0008] Silicon substrate;

[0009] N-type GaSb film on a silicon substrate;

[0010] A cascade thermophotovoltaic cell located on an N-type GaSb film, wherein the cascade thermophotovoltaic cell comprises a plurality of thermophotovoltaic cell units arranged in a stacked manner;

[0011] P-type GaSb film on cascade thermophotovoltaic cells;

[0012] The electrodes include a first electrode located on the P-type GaSb film and a second electrode located on the N-type GaSb film.

[0013] In one embodiment, the thermophotovoltaic cell unit is a PNIP structure, including a P-type GaSb layer, an N-type GaSb layer, an I-type InGaAsSb absorption layer and a P-type GaSb contact layer stacked from bottom to top, wherein the P-type GaSb layer and the N-type GaSb layer form a tunnel junction for transmitting the electrical signal generated by the I-type InGaAsSb absorption layer.

[0014] In one embodiment, the thickness of the P-type GaSb layer is 10-50 nm, the thickness of the N-type GaSb layer is 10-50 nm, the thickness of the I-type InGaAsSb absorption layer is 100-500 nm, and the thickness of the P-type GaSb contact layer is 10-50 nm.

[0015] In one embodiment, the cascade thermophotovoltaic cell includes 2 to 100 stacked thermophotovoltaic cell units.

[0016] In one embodiment, the surface crystal orientation of the silicon substrate is <100> ; and / or, the silicon substrate is an N-type silicon substrate, or a P-type silicon substrate, or a semi-edge silicon substrate.

[0017] In one embodiment, the material of the N-type GaSb film is single crystal GaSb; and / or the thickness of the N-type GaSb film is 500-2000 nm.

[0018] In one embodiment, the thickness of the P-type GaSb film is 100-500 nm.

[0019] Another embodiment of the present invention provides a technical solution as follows:

[0020] A method for preparing a silicon-based thermophotovoltaic cell, the method comprising:

[0021] S1. Provide a silicon substrate;

[0022] S2, preparing an N-type GaSb film on a silicon substrate;

[0023] S3, preparing a cascade thermophotovoltaic cell on an N-type GaSb film, wherein the cascade thermophotovoltaic cell comprises a plurality of thermophotovoltaic cell units arranged in a stacked manner;

[0024] S4, preparing a P-type GaSb film on a cascade thermophotovoltaic cell;

[0025] S5, preparing a first electrode on the P-type GaSb film;

[0026] S6. Prepare a second electrode on the N-type GaSb film.

[0027] In one embodiment, the method for preparing the cascade thermophotovoltaic cell comprises:

[0028] S31, preparing a P-type GaSb layer;

[0029] S32, preparing an N-type GaSb layer on the P-type GaSb layer;

[0030] S33, preparing an I-type InGaAsSb absorption layer on the N-type GaSb layer;

[0031] S34, preparing a P-type GaSb contact layer on the I-type InGaAsSb absorption layer;

[0032] S35 , repeating steps S31 to S34 to form a plurality of stacked thermophotovoltaic cell units.

[0033] In one embodiment, the preparation process in steps S2 to S4 is a metal organic chemical vapor deposition process or a molecular beam epitaxy process.

[0034] The present invention has the following beneficial effects:

[0035] The present invention can effectively absorb photons by introducing cascaded thermophotovoltaic cells, ensuring quantum efficiency and simple preparation, effectively overcoming the shortcomings of traditional thermophotovoltaic cells, and can achieve mass production and large-scale application; at the same time, the use of silicon substrates can greatly reduce production costs, which is conducive to market applications. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0037] Figure 1 It is a schematic diagram of the structure of the silicon-based thermophotovoltaic cell in the present invention;

[0038] Figure 2 It is a schematic structural diagram of a thermal photovoltaic cell unit in the present invention;

[0039] Figure 3 Schematic diagram of the energy band of the thermal photovoltaic cell unit in the present invention;

[0040] Figure 4 The process flow chart of the method for preparing silicon-based thermophotovoltaic cells in the present invention;

[0041] Figure 5 The process flow chart of the method for preparing cascade thermophotovoltaic cells in the present invention. DETAILED DESCRIPTION

[0042] In order to enable those skilled in the art to better understand the technical solutions in the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of the present invention.

[0043] Ginseng Figure 1 As shown, the present invention discloses a silicon-based thermal photovoltaic cell, which includes:

[0044] Silicon substrate 10;

[0045] An N-type GaSb film 20 located on a silicon substrate;

[0046] A cascade thermophotovoltaic cell 30 located on an N-type GaSb film, the cascade thermophotovoltaic cell comprising a plurality of thermophotovoltaic cell units arranged in a stacked manner;

[0047] A P-type GaSb film 40 located on a cascade thermophotovoltaic cell;

[0048] The electrodes include a first electrode 51 located on the P-type GaSb film and a second electrode 52 located on the N-type GaSb film.

[0049] Combination Figure 2 As shown, the thermophotovoltaic cell unit in the present invention is a PNIP structure, including a P-type GaSb layer 31, an N-type GaSb layer 32, an I-type InGaAsSb absorption layer 33 and a P-type GaSb contact layer 34 stacked from bottom to top.

[0050] Combination Figure 3 As shown, the P-type GaSb layer and the N-type GaSb layer form a tunnel junction for transmitting the electrical signal generated by the I-type InGaAsSb absorption layer, and the tunnel junction is used to transmit signals between adjacent thermophotovoltaic cell units. Preferably, the thickness of the P-type GaSb layer is 10 to 50 nm, the thickness of the N-type GaSb layer is 10 to 50 nm, the thickness of the I-type InGaAsSb absorption layer is 100 to 500 nm, and the thickness of the P-type GaSb contact layer is 10 to 50 nm.

[0051] In order to reduce the dark current, the thickness of the InGaAsSb absorption layer of the present invention is less than the minority carrier diffusion length of the absorption layer at the operating temperature. Preferably, the thickness of the absorption region is 100 to 500 nm, while the thickness of the thermophotovoltaic cell in the prior art is usually above 2 μm. When the thickness of the absorption region is less than the minority carrier diffusion length, the device dark current is proportional to the thickness of the absorption layer. The absorption region thickness of the present invention is only 100 to 500 nm, so it can effectively reduce the device dark current.

[0052] The cascaded thermophotovoltaic cell of the present invention includes 2 to 100 stacked thermophotovoltaic cell units, and the specific number of thermophotovoltaic cell units needs to be designed according to actual needs. The thermophotovoltaic cell units are all based on an Al-free PINP structure, and the P-type GaSb layer and the N-type GaSb layer form a tunnel junction, which is effectively simplified in design, reducing the difficulty of material growth and device processing, and the cascade structure of multiple thermophotovoltaic cell units can effectively absorb photons, ensuring quantum efficiency.

[0053] In order to reduce the cost of battery preparation, the silicon substrate used in the present invention has a greater price advantage than the traditional III-V substrate and is more conducive to large-scale growth. Preferably, the surface crystal orientation of the silicon substrate is <100> ; The silicon substrate is an N-type silicon substrate, a P-type silicon substrate, or a semi-insulated silicon substrate.

[0054] Preferably, the material of the N-type GaSb film in the present invention is single crystal GaSb, and the thickness of the N-type GaSb film is 500-2000 nm; the thickness of the P-type GaSb film is 100-500 nm.

[0055] Ginseng Figure 4 As shown, the method for preparing a silicon-based thermal photovoltaic cell in the present invention comprises the following steps:

[0056] S1. Provide a silicon substrate;

[0057] S2, preparing an N-type GaSb film on a silicon substrate;

[0058] S3, preparing a cascade thermophotovoltaic cell on an N-type GaSb film, wherein the cascade thermophotovoltaic cell comprises a plurality of thermophotovoltaic cell units arranged in a stacked manner;

[0059] S4, preparing a P-type GaSb film on a cascade thermophotovoltaic cell;

[0060] S5, preparing a first electrode on the P-type GaSb film;

[0061] S6. Prepare a second electrode on the N-type GaSb film.

[0062] The preparation order of the first electrode and the second electrode in the present invention is not limited. The first electrode can be prepared first and then the second electrode, or the second electrode can be prepared first and then the first electrode, or the first electrode and the second electrode can be prepared at the same time. In addition, the preparation of the second electrode can be completed after the preparation of the P-type GaSb film, or before the preparation of the cascade thermophotovoltaic cell, which will not be described in detail here.

[0063] Combination Figure 5 As shown, the method for preparing a cascade thermophotovoltaic cell comprises the following steps:

[0064] S31, preparing a P-type GaSb layer;

[0065] S32, preparing an N-type GaSb layer on the P-type GaSb layer;

[0066] S33, preparing an I-type InGaAsSb absorption layer on the N-type GaSb layer;

[0067] S34, preparing a P-type GaSb contact layer on the I-type InGaAsSb absorption layer;

[0068] S35 , repeating steps S31 to S34 to form a plurality of stacked thermophotovoltaic cell units.

[0069] Preferably, the preparation process in steps S2 to S4 of the present invention is a metal organic chemical vapor deposition process or a molecular beam epitaxy process.

[0070] The present invention is further described below in conjunction with specific embodiments.

[0071] A silicon-based thermophotovoltaic cell in a specific embodiment of the present invention comprises:

[0072] Silicon substrate, select surface crystal orientation <100> N-type silicon substrate;

[0073] N-type GaSb film on silicon substrate, 1500nm thick;

[0074] A cascade thermophotovoltaic cell located on an N-type GaSb film, the cascade thermophotovoltaic cell comprising a plurality of thermophotovoltaic cell units arranged in a stacked manner;

[0075] P-type GaSb film on cascade thermophotovoltaic cell, 100nm thick;

[0076] The electrodes include a first electrode (anode) located on the P-type GaSb film and a second electrode (cathode) located on the N-type GaSb film, wherein the first electrode is A combination of The second electrode is A combination of and the second electrode and the cascaded thermophotovoltaic cell are independent of each other and are not repeated.

[0077] The thickness of the P-type GaSb layer is 20 nm, the thickness of the N-type GaSb layer is 20 nm, the thickness of the I-type InGaAsSb absorption layer is 200 nm, and the thickness of the P-type GaSb contact layer is 40 nm.

[0078] The preparation method of the silicon-based thermophotovoltaic cell in this embodiment specifically includes:

[0079] Surface crystal orientation <100> The N-type silicon substrate is placed in a MOCVD epitaxial device for high-temperature annealing at 950°C for 5 minutes, then cooled to 450°C. After the temperature stabilizes, AsH3 and TMIn are used as precursors to grow 5nm thick InAs; the temperature is further raised to 520°C and stabilized, TMSb and TEGa are used as precursors, and DETe is used as a doping source to grow a 1500nm N-type GaSb film, thus completing the growth of the GaSb pseudo substrate;

[0080] At 520℃, grow a thermal photovoltaic cell unit, use TMSb and TEGa as precursors, CBr4 as a doping source, grow a 20nm thick P-type GaSb layer; continue to use TMSb and TEGa as precursors, DETe as a doping source, grow a 20nm thick N-type GaSb layer; continue to use TMSb, TEGa, TMIn and AsH3 as precursors, grow a 200nm thick InGaAsSb absorption layer; finally, use TMSb and TEGa as precursors, SiH4 as a doping source, grow a 40nm thick P-type GaSb contact layer, thus completing the growth of a cycle of thermal photovoltaic cell units;

[0081] After the growth of the stacked thermal photovoltaic cell unit is completed, a P-type GaSb film with a thickness of 100 nm is grown on the surface layer, using TMSb and TEGa as precursors and CBr4 as a doping source, thus completing the growth of the cascade thermal photovoltaic cell;

[0082] The first electrode (anode) is deposited on the P-type GaSb film. A combination of combination.

[0083] The second electrode (cathode) is set on the N-type GaSb film. That is to say, the lower electrode and the absorption region are independent of each other and do not overlap. The second electrode adopts A combination of combination.

[0084] It can be seen from the above technical solutions that the present invention has the following advantages:

[0085] The present invention can effectively absorb photons by introducing cascaded thermophotovoltaic cells, ensuring quantum efficiency and simple preparation, effectively overcoming the shortcomings of traditional thermophotovoltaic cells, and can achieve mass production and large-scale application; at the same time, the use of silicon substrates can greatly reduce production costs, which is conducive to market applications.

[0086] It will be apparent to those skilled in the art that the invention is not limited to the details of the exemplary embodiments described above and that the invention can be implemented in other specific forms without departing from the spirit or essential features of the invention. Therefore, the embodiments should be considered exemplary and non-limiting in all respects, and the scope of the invention is defined by the appended claims rather than the foregoing description, and it is intended that all variations falling within the meaning and scope of the equivalent elements of the claims be included in the invention. Any reference numeral in a claim should not be considered as limiting the claim to which it relates.

[0087] In addition, it should be understood that although the present specification is described according to implementation modes, not every implementation mode contains only one independent technical solution. This description of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment may also be appropriately combined to form other implementation modes that can be understood by those skilled in the art.

Claims

1. A silicon-based thermophotovoltaic cell, characterized in that: The silicon-based thermal photovoltaic cell comprises: Silicon substrate; N-type GaSb film on a silicon substrate; A cascade thermophotovoltaic cell located on an N-type GaSb film, wherein the cascade thermophotovoltaic cell comprises a plurality of thermophotovoltaic cell units arranged in a stacked manner; P-type GaSb film on cascade thermophotovoltaic cells; Electrodes, including a first electrode located on the P-type GaSb film and a second electrode located on the N-type GaSb film; The thermophotovoltaic cell unit is a PNIP structure, comprising a P-type GaSb layer, an N-type GaSb layer, an I-type InGaAsSb absorption layer and a P-type GaSb contact layer stacked from bottom to top, wherein the P-type GaSb layer and the N-type GaSb layer form a tunnel junction for transmitting the electrical signal generated by the I-type InGaAsSb absorption layer; The thickness of the P-type GaSb layer is 10-50 nm, the thickness of the N-type GaSb layer is 10-50 nm, the thickness of the I-type InGaAsSb absorption layer is 100-500 nm, and the thickness of the P-type GaSb contact layer is 10-50 nm.

2. The silicon-based thermophotovoltaic cell according to claim 1, characterized in that: The cascade thermophotovoltaic cell comprises 2 to 100 stacked thermophotovoltaic cell units.

3. The silicon-based thermophotovoltaic cell according to claim 1, characterized in that: The surface crystal orientation of the silicon substrate is <100> ; and / or, the silicon substrate is an N-type silicon substrate, or a P-type silicon substrate, or a semi-edge silicon substrate.

4. The silicon-based thermophotovoltaic cell according to claim 1, characterized in that: The material of the N-type GaSb film is single crystal GaSb; and / or the thickness of the N-type GaSb film is 500-2000 nm.

5. The silicon-based thermophotovoltaic cell according to claim 1, characterized in that: The thickness of the P-type GaSb film is 100-500 nm.

6. A method for preparing a silicon-based thermophotovoltaic cell, characterized in that: The preparation method comprises: S1. Provide a silicon substrate; S2, preparing an N-type GaSb film on a silicon substrate; S3, preparing a cascade thermophotovoltaic cell on an N-type GaSb film, wherein the cascade thermophotovoltaic cell comprises a plurality of thermophotovoltaic cell units arranged in a stacked manner; S4, preparing a P-type GaSb film on a cascade thermophotovoltaic cell; S5, preparing a first electrode on the P-type GaSb film; S6, preparing a second electrode on the N-type GaSb film; The preparation method of the cascade thermophotovoltaic cell comprises: S31, preparing a P-type GaSb layer; S32, preparing an N-type GaSb layer on the P-type GaSb layer; S33, preparing an I-type InGaAsSb absorption layer on the N-type GaSb layer; S34, preparing a P-type GaSb contact layer on the I-type InGaAsSb absorption layer; S35, repeating steps S31 to S34 to form a plurality of stacked thermophotovoltaic cell units; The thickness of the P-type GaSb layer is 10-50 nm, the thickness of the N-type GaSb layer is 10-50 nm, the thickness of the I-type InGaAsSb absorption layer is 100-500 nm, and the thickness of the P-type GaSb contact layer is 10-50 nm.

7. The preparation method according to claim 6, characterized in that: The preparation process in steps S2 to S4 is a metal organic chemical vapor deposition process or a molecular beam epitaxy process.

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