Photoelectric detector and preparation method
By introducing a zinc sulfide layer on the MoS2 substrate to form a MoS2-ZnS heterostructure, the problem of weak response ability of MoS2 devices in the ultraviolet band is solved, and full spectrum response and high detection from ultraviolet to near-infrared are achieved, which is suitable for CMOS integration.
Patent Information
- Application Number
- CN202511213791.0
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-08-27
- Publication Date
- 2025-10-17
AI Technical Summary
Existing MoS2 devices have weak response capabilities in the ultraviolet band, and high photoelectric output is accompanied by slow response and high dark current.
A zinc sulfide layer is introduced on the MoS2 substrate to form a MoS2-ZnS heterostructure, which is combined with a silicon substrate to form a Type-I heterojunction. The built-in electric field suppresses the recombination of photogenerated carriers, and device miniaturization is achieved through CMOS integration.
It achieves full spectrum response from ultraviolet to near-infrared, improves responsiveness and detection, has a response time of microseconds, and is easy to integrate with existing silicon-based circuits.
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Abstract
Description
TECHNICAL FIELD
[0001] The present application relates to the technical field of photoelectric detectors, in particular to a photoelectric detector and a preparation method. BACKGROUND
[0002] In recent years, as a typical two-dimensional transition metal dichalcogenide (TMD), MoS2 has become a research hotspot in the field of visible and near-infrared photoelectric detection due to its adjustable band gap (1.2-1.8eV), high carrier mobility, and strong light-matter interaction in thin layers. However, single MoS2 devices have weak response capability in the ultraviolet band, and high photoelectric output is often accompanied by slow response and high dark current. To make up for the lack of spectral response, researchers generally use the heterojunction strategy to introduce other materials on the MoS2 substrate to broaden the detection band and improve the response performance. SUMMARY
[0003] An object of the present application is to provide a photoelectric detector to solve the technical problem of weak response capability of single MoS2 devices in the ultraviolet band in the prior art.
[0004] Another object of the present application is to provide a preparation method for the photoelectric detector.
[0005] In particular, the present application also provides a photoelectric detector, comprising a silicon substrate, a functional layer, an electrode layer and an insulating layer. The silicon substrate comprises an n-type silicon layer and a p-type silicon layer arranged in a stack from bottom to top. The functional layer is located above the silicon substrate and comprises a molybdenum disulfide layer and a zinc sulfide layer arranged in a stack from bottom to top.
[0006] Optionally, the p-type silicon layer comprises a first doped layer, the insulating layer is located above the p-type silicon layer and in contact with the first doped layer, the insulating layer has a first groove in the middle, and the functional layer is located in the first groove.
[0007] Optionally, the insulating layer has a plurality of second grooves, and the electrode layer comprises a first electrode layer and a second electrode layer. The first electrode layer is located in the second groove and in contact with the first doped layer, and the top of the first electrode layer is higher than the insulating layer. The second electrode layer is located at the bottom of the n-type silicon layer.
[0008] Optionally, the electrode layer comprises a first electrode layer and a second electrode layer, part of the first electrode layer is located above the insulating layer, and the other part is located above the functional layer. The second electrode layer is located at the bottom of the n-type silicon layer.
[0009] Optionally, the insulating layer has a plurality of second grooves, the electrode layer includes a first electrode layer and a second electrode layer, the first electrode layer and the second electrode layer are respectively located in different second grooves, and the top of the first electrode layer and the second electrode layer is higher than the corresponding second groove, and the first electrode layer and the second electrode layer are both in contact with the first doped layer.
[0010] Optionally, the insulating layer has a plurality of second grooves, the electrode layer includes a first electrode layer and a second electrode layer, the first electrode layer is located in the second groove, and the top is higher than the second groove, and part of the second electrode layer is located above the insulating layer, and another part is located above the functional layer.
[0011] Optionally, the n-type silicon layer includes a second doped layer, the n-type silicon layer has a deep silicon groove opening downward and corresponding to the second doped layer; the insulating layer is located below the n-type silicon layer and has a through hole corresponding to the deep silicon groove; The electrode layer is filled in the deep silicon groove and the through hole, and is in contact with the second doped layer, and the lower surface of the electrode layer protrudes from the insulating layer.
[0012] In particular, the present application also provides a preparation method of a photodetector, applied to the photodetector described above, comprising the following steps: Providing a silicon substrate, the silicon substrate includes an n-type silicon layer and a p-type silicon layer arranged in a stack from bottom to top; Performing an oxidation layer deposition, a glue coating, a photolithography and an ion implantation process on the p-type silicon layer in sequence, thereby forming a first doped layer; Performing an insulating layer deposition, a glue coating, a photolithography and an etching process on the p-type silicon layer in sequence, thereby forming an insulating layer with a first groove; Spin-coating a molybdenum disulfide precursor solution and a zinc sulfide precursor solution on the first groove in sequence, thereby forming a molybdenum disulfide layer and a zinc sulfide layer respectively; Performing a glue coating, a photolithography and an etching process on the insulating layer in sequence, thereby forming a plurality of second grooves, the second grooves being located above the first doped layer; Performing a deposition, a glue coating, a photolithography and an etching process in the second groove in sequence, thereby forming a first electrode layer, and depositing a second electrode layer at the bottom of the n-type silicon layer.
[0013] In particular, the present application also provides a preparation method of a photodetector, applied to the photodetector described above, comprising the following steps: Providing a silicon substrate, the silicon substrate includes an n-type silicon layer and a p-type silicon layer arranged in a stack from bottom to top; Depositing an oxidation layer, coating, photoetching and ion implanting on the p-type silicon layer in sequence to form a first doped layer; Depositing an insulation layer, coating, photoetching and etching on the p-type silicon layer in sequence to form an insulation layer with a first groove; Spin-coating a molybdenum disulfide precursor solution and a zinc sulfide precursor solution on the first groove in sequence to form a molybdenum disulfide layer and a zinc sulfide layer, respectively; Depositing, coating, photoetching and etching on the insulation layer and the functional layer in sequence to form a first electrode layer, and depositing a second electrode layer at the bottom of the n-type silicon layer.
[0014] In particular, the present application also provides a preparation method of a photodetector, applied to the photodetector described above, comprising the following steps: Providing a silicon substrate, the silicon substrate comprising an n-type silicon layer and a p-type silicon layer arranged in sequence from bottom to top; Depositing an oxidation layer, coating, photoetching and ion implanting on the p-type silicon layer in sequence to form a first doped layer; Depositing an insulation layer, coating, photoetching and etching on the p-type silicon layer in sequence to form an insulation layer with a first groove; Spin-coating a molybdenum disulfide precursor solution and a zinc sulfide precursor solution on the first groove in sequence to form a molybdenum disulfide layer and a zinc sulfide layer, respectively; Coating, photoetching and etching on the insulation layer in sequence to form a plurality of second grooves, the second grooves being located above the first doped layer; Depositing, coating, photoetching and etching in different second grooves in sequence to form a first electrode layer and a second electrode layer, respectively.
[0015] In particular, the present application also provides a preparation method of a photodetector, applied to the photodetector described above, comprising the following steps: Providing a silicon substrate, the silicon substrate comprising an n-type silicon layer and a p-type silicon layer arranged in sequence from bottom to top; Depositing an oxidation layer, coating, photoetching and ion implanting on the p-type silicon layer in sequence to form a first doped layer; Depositing an insulation layer, coating, photoetching and etching on the p-type silicon layer in sequence to form an insulation layer with a first groove; Spin-coating a molybdenum disulfide precursor solution and a zinc sulfide precursor solution on the first groove in sequence to form a molybdenum disulfide layer and a zinc sulfide layer, respectively; Coating, photoetching and etching on the insulation layer in sequence to form a plurality of second grooves, the second grooves being located above the first doped layer; Deposition, glue coating, photoetching and etching processes are sequentially performed in the second groove, thereby forming a first electrode layer; Deposition, glue coating, photoetching and etching processes are sequentially performed on the insulating layer and the functional layer, thereby forming a second electrode layer.
[0016] In particular, the application further provides a preparation method of the photodetector, applied to the photodetector described above, comprising the following steps: A silicon substrate is provided, which comprises an n-type silicon layer and a p-type silicon layer arranged in a stack from bottom to top, and the top of the n-type silicon layer has a second doped layer; A molybdenum disulfide layer, a zinc sulfide layer and an ITO layer are sequentially deposited on the p-type silicon layer; Etching is performed on the bottom of the n-type silicon layer to form a deep silicon groove which is downwardly open and arranged corresponding to the second doped layer; An electrode material is filled in the deep silicon groove to form an electrode layer, and the bottom of the electrode layer protrudes out of the deep silicon groove; An insulating layer is deposited on the bottom of the n-type silicon layer.
[0017] The photodetector in the application comprises a silicon substrate, a functional layer, an electrode layer and an insulating layer. The silicon substrate comprises an n-type silicon layer and a p-type silicon layer arranged in a stack from bottom to top. The functional layer is above the silicon substrate and comprises a molybdenum disulfide layer and a zinc sulfide layer arranged in a stack from bottom to top. The above technical solution introduces the zinc sulfide layer on the molybdenum disulfide layer to form a MoS2-ZnS heterostructure. The wide band gap of ZnS makes up for the response blind area of MoS2 to ultraviolet light, and MoS2 covers visible and near-infrared light, thereby realizing UV-Vis-NIR full spectrum. Type-I heterojunction is formed between the MoS2-ZnS heterostructure, the built-in electric field effectively inhibits the recombination of photo-generated carriers, and the electron mobility is high, thereby improving the responsivity and detectivity. In addition, the MoS2-ZnS heterostructure based on the silicon substrate is easy to integrate with CMOS, thereby realizing device miniaturization and high integration.
[0018] The above and other objects, advantages and features of the application will become more apparent from the following detailed description of some embodiments thereof, when considered in conjunction with the attached drawings. BRIEF DESCRIPTION OF DRAWINGS
[0019] Some specific embodiments of the application will be described in detail below with reference to the attached drawings, which are provided by way of example and are not limiting of the application. Identical reference numbers in the figures designate identical or similar elements or parts. Persons skilled in the art will appreciate that the figures are not necessarily drawn to scale. In the figures: Figure 1 is a schematic structural diagram of a photodetector according to a first embodiment of the application; Figure 2 is a schematic structural diagram of a photodetector according to a second embodiment of the present application; Figure 3 is a schematic structural diagram of a photodetector according to a third embodiment of the present application; Figure 4 is a schematic structural diagram of a photodetector according to a fourth embodiment of the present application; Figure 5 is a schematic structural diagram of a photodetector according to a fifth embodiment of the present application; Figure 6 is a schematic flow chart of a method for manufacturing a photodetector according to a first embodiment of the present application; Figure 7 is a schematic diagram of a method for manufacturing a photodetector according to a first embodiment of the present application; Figure 8 is a schematic flow chart of a method for manufacturing a photodetector according to a second embodiment of the present application; Figure 9 is a schematic diagram of a method for manufacturing a photodetector according to a second embodiment of the present application; Figure 10 is a schematic flow chart of a method for manufacturing a photodetector according to a third embodiment of the present application; Figure 11 is a schematic diagram of a method for manufacturing a photodetector according to a third embodiment of the present application; Figure 12 is a schematic flow chart of a method for manufacturing a photodetector according to a fourth embodiment of the present application; Figure 13 is a schematic diagram of a method for manufacturing a photodetector according to a fourth embodiment of the present application; Figure 14 is a schematic flow chart of a method for manufacturing a photodetector according to a fifth embodiment of the present application; Figure 15 is a schematic diagram of a method for manufacturing a photodetector according to a fifth embodiment of the present application.
[0020] Reference signs: 100 - photodetector, 10 - silicon substrate, 11 - n-type silicon layer, 12 - p-type silicon layer, 13 - first doped layer, 20 - insulating layer, 30 - electrode layer, 31 - first electrode layer, 32 - second electrode layer, 40 - functional layer, 41 - molybdenum disulfide layer, 42 - zinc sulfide layer, 43 - ITO layer, 111 - second doped layer, 112 - deep silicon trench. DETAILED DESCRIPTION
[0021] The following describes embodiments of the present invention in detail, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to be used to explain the present invention, and are not to be construed as limiting the present invention.
[0022] Figure 1 FIG is a schematic structural diagram of a photodetector 100 according to a first embodiment of the present invention. Figure 1 As shown, in the first embodiment, the photodetector 100 includes a silicon substrate 10, a functional layer 40, an electrode layer 30, and an insulating layer 20. The silicon substrate 10 includes an n-type silicon layer 11 and a p-type silicon layer 12 stacked sequentially from bottom to top. The functional layer 40 is located above the silicon substrate 10 and includes a molybdenum disulfide layer 41 and a zinc sulfide layer 42 stacked sequentially from bottom to top. The silicon substrate 10 here can be an epitaxial or single crystal silicon substrate.
[0023] In this embodiment, a zinc sulfide layer 42 is introduced onto the molybdenum disulfide layer 41 to form a MoS2-ZnS heterostructure. The wide bandgap of ZnS fills the blind spot of MoS2's response to ultraviolet light, while MoS2 covers visible and near-infrared light, thus achieving the full UV-Vis-NIR spectrum. A Type-I heterojunction is formed between the MoS2-ZnS heterostructures. The built-in electric field effectively suppresses the recombination of photogenerated carriers, and the electron mobility is high, thereby improving the responsivity and detectivity. The responsivity can be as high as about 9A / W, and the detectivity can be as high as about 10 14 Jones, the response time can reach the µs level. Furthermore, the MoS2-ZnS heterostructure based on silicon substrate 10 is easily integrated with CMOS, enabling device miniaturization and high integration. The vertical heterostructure and short current-carrying path formed in this embodiment facilitates achieving a microsecond-level or faster optical response.
[0024] In some embodiments, the p-type silicon layer 12 includes a first doped layer 13 . The insulating layer 20 is located above the p-type silicon layer 12 and in contact with the first doped layer 13 . The insulating layer 20 has a first trench in the middle, and the functional layer 40 is located in the first trench.
[0025] In some embodiments, the insulating layer 20 has a plurality of second trenches, and the electrode layer 30 includes a first electrode layer 31 and a second electrode layer 32. The first electrode layer 31 is located within the second trenches and contacts the first doped layer 13. The top of the first electrode layer 31 is higher than the insulating layer 20. The second electrode layer 32 is located at the bottom of the n-type silicon layer 11. It can be understood that the photodetector 100 of this embodiment has a top-bottom electrode structure.
[0026] In some embodiments, the photodetector 100 further includes an ITO layer 43 , which is located above the zinc sulfide layer 42 .
[0027] Figure 2 FIG is a schematic structural diagram of a photodetector 100 according to a second embodiment of the present invention. Figure 2 As shown, the second embodiment differs from the first embodiment only in that the electrode layer 30 includes a first electrode layer 31 and a second electrode layer 32, wherein a portion of the first electrode layer 31 is located above the insulating layer 20, and another portion is located above the functional layer 40. The second electrode layer 32 is located at the bottom of the n-type silicon layer 11.
[0028] This embodiment forms an external electric field by applying voltage, which can promote the separation of carrier-hole pairs and improve detection efficiency compared to the original built-in electric field. At the same time, it can increase the response speed of the detector under the action of the external electric field.
[0029] Figure 3 FIG is a schematic structural diagram of a photodetector 100 according to a third embodiment of the present invention. Figure 3 As shown, the third embodiment differs from the first embodiment only in that the insulating layer 20 has a plurality of second grooves, the electrode layer 30 includes a first electrode layer 31 and a second electrode layer 32, the first electrode layer 31 and the second electrode layer 32 are respectively located in different second grooves, and the tops of the first electrode layer 31 and the second electrode layer 32 are higher than the corresponding second grooves, and the first electrode layer 31 and the second electrode layer 32 are both in contact with the first doping layer 13.
[0030] Figure 4 FIG is a schematic structural diagram of a photodetector 100 according to a fourth embodiment of the present invention. Figure 4 As shown, the fourth embodiment differs from the first embodiment only in that the insulating layer 20 has a plurality of second grooves, the electrode layer 30 includes a first electrode layer 31 and a second electrode layer 32, the first electrode layer 31 is located in the second grooves, and the top is higher than the second grooves, a portion of the second electrode layer 32 is located above the insulating layer 20, and another portion is located above the functional layer 40.
[0031] Figure 5 FIG is a schematic structural diagram of a photodetector 100 according to a fifth embodiment of the present invention. Figure 5 As shown, in the fifth embodiment, the n-type silicon layer 11 includes a second doped layer 111, and the n-type silicon layer 11 has a deep silicon trench 112 with a downward opening corresponding to the second doped layer 111. The insulating layer 20 is located below the n-type silicon layer 11 and has a through hole corresponding to the deep silicon trench 112. The electrode layer 30 fills the deep silicon trench 112 and the through hole and contacts the second doped layer 111. The lower surface of the electrode layer 30 protrudes above the insulating layer 20.
[0032] In some embodiments, the photodetector 100 further includes an ITO layer 43 , which is located above the zinc sulfide layer 42 .
[0033] The MoS2-ZnS heterostructure of this embodiment realizes a single device covering a 300nm-1000nm or even wider spectrum, eliminating the ultraviolet blind area. In addition, the MoS2-ZnS device is manufactured on the silicon substrate 10, has a scale-up preparation condition, and can be seamlessly combined with the existing silicon-based circuit.
[0034] Figure 6 is a schematic flowchart of a preparation method of the photoelectric detector 100 according to the first embodiment of the present application, Figure 7 is a schematic diagram of the preparation method of the photoelectric detector 100 according to the first embodiment of the present application. As shown in Figure 6 and Figure 7 shown, in the first embodiment, the preparation method of the photoelectric detector 100 is applied to the photoelectric detector 100 as shown in Figure 1 The preparation method of the photoelectric detector 100 includes the following steps: Step S1, providing a silicon substrate 10, the silicon substrate 10 includes an n-type silicon layer 11 and a p-type silicon layer 12 arranged in a bottom-up order, see Figure 7 (1) in the figure; Step S2, sequentially performing an oxidation layer deposition, a glue coating, a photoetching and an ion implantation process on the p-type silicon layer 12, thereby forming a first doped layer 13, see Figure 7 (2) in the figure; Step S3, sequentially performing an insulation layer 20 deposition, a glue coating, a photoetching and an etching process on the p-type silicon layer 12, thereby forming the insulation layer 20 with a first groove, see Figure 7 (3) in the figure; Step S4, sequentially spin-coating a molybdenum disulfide precursor solution and a zinc sulfide precursor solution at the first groove, thereby forming a molybdenum disulfide layer 41 and a zinc sulfide layer 42, respectively, see Figure 7 (4) in the figure; Step S5, sequentially performing a glue coating, a photoetching and an etching process on the insulation layer 20, thereby forming a plurality of second grooves, the second grooves being located above the first doped layer 13; Step S6, sequentially performing a deposition, a glue coating, a photoetching and an etching process in the second groove, thereby forming a first electrode layer 31, and depositing a second electrode layer 32 at the bottom of the n-type silicon layer 11, see Figure 7 (5) in the figure.
[0035] After step S4, the following steps are further included: Step S41, performing a patterning process on the zinc sulfide layer 42 to obtain a zinc sulfide layer 42 with a first preset pattern. Here, the first preset pattern can be determined according to specific design requirements.
[0036] Step S42, depositing an ITO layer 43 on the zinc sulfide layer 42, referring to Figure 7 FIG. 4; Step S43, performing a patterning process on the ITO layer 43 to obtain an ITO layer 43 with a second preset pattern. Here, the second preset pattern can be determined according to specific design requirements.
[0037] In this embodiment, the materials of the first electrode layer 31 and the second electrode layer 32 are both aluminum. The material of the insulating layer 20 is silicon dioxide. In other embodiments, the materials of the first electrode layer 31, the second electrode layer 32 and the insulating layer 20 can also be determined according to specific design requirements.
[0038] In step S4, the MoS2 layer is grown by a hydrothermal method. The molybdenum disulfide precursor solution is first reacted at 200°C for 20h, and finally dried at 80°C to form the MoS2 layer. Here, the molybdenum disulfide precursor solution contains a molybdenum source and a sulfur source. In addition, the ZnS layer is grown by a hydrothermal method. The zinc sulfide precursor solution is first reacted at 200°C for 1h, and finally dried at 80°C to form the ZnS layer. Here, the zinc sulfide precursor solution contains a sulfur source and a zinc source.
[0039] In some embodiments, the interface quality of MoS2-ZnS can be significantly optimized by annealing or surface passivation treatment.
[0040] Figure 8 is a schematic flow chart of a preparation method of a photodetector 100 according to a second embodiment of the present application, Figure 9 is a schematic diagram of a preparation method of a photodetector 100 according to the second embodiment of the present application. As shown in Figure 8 and Figure 9 In the second embodiment, the preparation method of the photodetector 100 is applied to the photodetector 100 as shown in Figure 2 The preparation method of the photodetector 100 includes the following steps: Step S11, providing a silicon substrate 10, the silicon substrate 10 including an n-type silicon layer 11 and a p-type silicon layer 12 arranged in a stack from bottom to top, referring to Figure 9 FIG. 11; Step S12, sequentially performing an oxidation layer deposition, a glue coating, a photolithography and an ion implantation process on the p-type silicon layer 12 to form a first doped layer 13, referring to Figure 9 FIG. 12; Step S13, sequentially performing an insulating layer 20 deposition, a glue coating, a photolithography and an etching process on the p-type silicon layer 12 to form an insulating layer 20 with a first groove, referring to Figure 9 FIG. 13; Step S14, spin-coating the molybdenum disulfide precursor solution and the zinc sulfide precursor solution in sequence at the first groove, so as to form the molybdenum disulfide layer 41 and the zinc sulfide layer 42 respectively, see Figure 9 Fig. 14; Step S15, performing deposition, glue coating, photoetching and etching processes in sequence on the insulating layer 20 and the functional layer 40, so as to form the first electrode layer 31, and depositing the second electrode layer 32 at the bottom of the n-type silicon layer 11, see Figure 9 Fig. 15.
[0041] Here, after step S14, the following steps are further included: Step S141, depositing the ITO layer 43 on the zinc sulfide layer 42, see Figure 9 Fig. 14.
[0042] Figure 10 is a schematic flow chart of a preparation method of the photodetector 100 according to the second embodiment of the present application, Figure 11 is a schematic diagram of the preparation method of the photodetector 100 according to the second embodiment of the present application. As shown in Figure 10 and Figure 11 shown in the third embodiment, the preparation method of the photodetector 100 is applied to the photodetector 100 shown in Figure 3 The preparation method of the photodetector 100 includes the following steps: Step S10, providing a silicon substrate 10, the silicon substrate 10 including an n-type silicon layer 11 and a p-type silicon layer 12 arranged in sequence from bottom to top, see Figure 11 Fig. 21; Step S21, performing the oxide layer deposition, glue coating, photoetching and ion implantation processes in sequence on the p-type silicon layer 12, so as to form the first doped layer 13, see Figure 11 Fig. 22. Step S22, performing the insulating layer 20 deposition, glue coating, photoetching and etching processes in sequence on the p-type silicon layer 12, so as to form the insulating layer 20 with the first groove, see Figure 11 Fig. 23. Step S23, spin-coating the molybdenum disulfide precursor solution and the zinc sulfide precursor solution in sequence at the first groove, so as to form the molybdenum disulfide layer 41 and the zinc sulfide layer 42 respectively, see Figure 11 Fig. 24. Step S24, performing the glue coating, photoetching and etching processes in sequence on the insulating layer 20, so as to form a plurality of second grooves, the second grooves being located above the first doped layer 13; Step S25, performing the deposition, glue coating, photoetching and etching processes in sequence in different second grooves, so as to form the first electrode layer 31 and the second electrode layer 32 respectively, seeFigure 11 Fig. 25.
[0043] After step S23, the following steps are further included: At step S231, the zinc sulfide layer 42 is subjected to a patterning process to obtain a zinc sulfide layer 42 with a third preset pattern. Here, the third preset pattern can be determined according to specific design requirements.
[0044] In this embodiment, the materials of the first electrode layer 31 and the second electrode layer 32 are both aluminum. The material of the insulating layer 20 is silicon dioxide. In other embodiments, the materials of the first electrode layer 31, the second electrode layer 32 and the insulating layer 20 can also be determined according to specific design requirements.
[0045] In step S23, the MoS2 layer is grown by a hydrothermal method. The molybdenum disulfide precursor solution is first reacted at 200°C for 20h, and finally dried at 80°C to form the MoS2 layer. Here, the molybdenum disulfide precursor solution contains a molybdenum source and a sulfur source. In addition, the ZnS layer is grown by a hydrothermal method. The zinc sulfide precursor solution is first reacted at 200°C for 1h, and finally dried at 80°C to form the ZnS layer. Here, the zinc sulfide precursor solution contains a sulfur source and a zinc source.
[0046] Figure 12 is a schematic flow chart of a preparation method of a photodetector 100 according to a fourth embodiment of the present application, Figure 13 is a schematic diagram of a preparation method of a photodetector 100 according to the fourth embodiment of the present application. As shown in Figure 12 and Figure 13 shown, in the fourth embodiment, the preparation method of the photodetector 100 is applied to the photodetector 100 as shown in Figure 4 The preparation method of the photodetector 100 includes the following steps: At step S31, a silicon substrate 10 is provided, which includes an n-type silicon layer 11 and a p-type silicon layer 12 arranged in a stacking manner from bottom to top, as shown in Figure 13 Fig. 31; At step S32, an oxidation layer deposition, a glue coating, a photolithography and an ion implantation process are sequentially performed on the p-type silicon layer 12, so as to form a first doped layer 13, as shown in Figure 13 Fig. 32; At step S33, an insulating layer deposition, a glue coating, a photolithography and an etching process are sequentially performed on the p-type silicon layer 12, so as to form an insulating layer 20 with a first groove, as shown in Figure 13 Fig. 33; At step S34, a molybdenum disulfide precursor solution and a zinc sulfide precursor solution are sequentially spin-coated at the first groove, so as to form a molybdenum disulfide layer 41 and a zinc sulfide layer 42, respectively, as shown in Figure 13 Fig. 34; Step S35, glueing, photoetching and etching processes are sequentially performed on the insulating layer 20, thereby forming a plurality of second grooves above the first doped layer 13; Step S36, deposition, glueing, photoetching and etching processes are sequentially performed in the second grooves, thereby forming the first electrode layer 31; Step S37, deposition, glueing, photoetching and etching processes are sequentially performed on the insulating layer 20 and the functional layer 40, thereby forming the second electrode layer 32, see Figure 13 FIG. 35.
[0047] Figure 14 is a schematic flow chart of a preparation method of the photoelectric detector 100 according to the fifth embodiment of the present application, Figure 15 is a schematic diagram of the preparation method of the photoelectric detector 100 according to the fifth embodiment of the present application. As shown in Figure 14 and Figure 15 shown in the fifth embodiment, the preparation method of the photoelectric detector 100 is applied to the photoelectric detector 100 shown in Figure 5 , the preparation method of the photoelectric detector 100 comprises the following steps: Step S100, providing a silicon substrate 10, the silicon substrate 10 comprises an n-type silicon layer 11 and a p-type silicon layer 12 arranged in a stack from bottom to top, the top of the n-type silicon layer 11 has a second doped layer 111, see Figure 15 FIG. 41; it can be understood that the silicon substrate 10 is an epitaxial wafer with a buried layer.
[0048] Step S200, sequentially depositing a molybdenum disulfide layer 41, a zinc sulfide layer 42 and an ITO layer 43 on the p-type silicon layer 12, see Figure 15 FIG. 42; Step S300, etching the bottom of the n-type silicon layer 11 to form a deep silicon groove 112 which is downwardly open and arranged corresponding to the second doped layer 111, see Figure 15 FIG. 43; Step S400, filling the electrode material in the deep silicon groove 112 to form an electrode layer 30, the bottom of the electrode layer 30 protrudes out of the deep silicon groove 112, see Figure 15 FIG. 44; Step S500, depositing the insulating layer 20 at the bottom of the n-type silicon layer 11, see Figure 15 FIG. 45.
[0049] In step S400, the top of the electrode layer 30 is in contact with the second doped layer 111.
[0050] In this embodiment, the material of the electrode layer 30 is copper, and the material of the insulating layer 20 is silicon dioxide. In other embodiments, the materials of the electrode layer 30 and the insulating layer 20 can also be determined according to specific design requirements.
[0051] This embodiment can also be extended to porous silicon, waveguide cavity or silicon photon structure, further improving the light absorption efficiency and device capacity, and the structure is flexible and diverse.
[0052] This embodiment constructs a MoS2-ZnS heterostructure photodetector 100 on a silicon substrate 10, which inherits the high response characteristics of MoS2 in the visible-near infrared light, and supplements the ultraviolet response space through ZnS. Combined with the manufacturing advantages of the silicon platform and the built-in electric field mechanism, it has the potential of wide spectrum, high sensitivity, fast response and high integration.
[0053] At this point, those skilled in the art should realize that although the present application has been shown and described in detail in the above embodiments, many other variations or modifications in accordance with the principles of the present application can be directly determined or deduced from the disclosure of the present application without departing from the spirit and scope of the present application. Therefore, the scope of the present application should be understood and recognized as covering all these other variations or modifications.
Claims
1. A photoelectric detector, characterized in that: including a silicon substrate, a functional layer, an electrode layer and an insulating layer; The silicon substrate comprises an n-type silicon layer and a p-type silicon layer stacked in sequence from bottom to top; The functional layer is located above the silicon substrate and includes a molybdenum disulfide layer and a zinc sulfide layer stacked in sequence from bottom to top.
2. The photodetector according to claim 1, wherein The p-type silicon layer includes a first doping layer. The insulating layer is located above the p-type silicon layer and contacts the first doping layer. A first trench is defined in the middle of the insulating layer. The functional layer is located in the first trench.
3. The photodetector according to claim 2, wherein: The insulating layer has a plurality of second grooves, and the electrode layer includes a first electrode layer and a second electrode layer; The first electrode layer is located in the second trench and in contact with the first doping layer, and a top of the first electrode layer is higher than the insulating layer; The second electrode layer is located at the bottom of the n-type silicon layer.
4. The photodetector according to claim 2, wherein: The electrode layer includes a first electrode layer and a second electrode layer, wherein a portion of the first electrode layer is located above the insulating layer, and another portion of the first electrode layer is located above the functional layer; The second electrode layer is located at the bottom of the n-type silicon layer.
5. The photodetector according to claim 2, wherein: The insulating layer has multiple second grooves, and the electrode layer includes a first electrode layer and a second electrode layer. The first electrode layer and the second electrode layer are respectively located in different second grooves, and the tops of the first electrode layer and the second electrode layer are higher than the corresponding second grooves. The first electrode layer and the second electrode layer are both in contact with the first doping layer.
6. The photodetector according to claim 2, wherein: The insulating layer has multiple second grooves, and the electrode layer includes a first electrode layer and a second electrode layer. The first electrode layer is located in the second grooves, and the top is higher than the second grooves. Part of the second electrode layer is located above the insulating layer, and the other part is located above the functional layer.
7. The photodetector according to claim 1, wherein The n-type silicon layer includes a second doped layer, and the n-type silicon layer has a deep silicon trench with an opening facing downward and corresponding to the second doped layer; The insulating layer is located below the n-type silicon layer and has a through hole corresponding to the deep silicon trench; The electrode layer is filled in the deep silicon trench and the through hole and is in contact with the second doping layer. The lower surface of the electrode layer protrudes from the insulating layer.
8. A method for preparing a photodetector, applied to the photodetector according to any one of claims 1 to 3, characterized in that: The steps include: Providing a silicon substrate, wherein the silicon substrate comprises an n-type silicon layer and a p-type silicon layer stacked sequentially from bottom to top; performing oxide layer deposition, resist coating, photolithography and ion implantation processes on the p-type silicon layer in sequence, thereby forming a first doping layer; performing insulating layer deposition, resist coating, photolithography, and etching processes on the p-type silicon layer in sequence, thereby forming an insulating layer having a first trench; Spin-coating a molybdenum disulfide precursor solution and a zinc sulfide precursor solution in sequence at the first groove to form a molybdenum disulfide layer and a zinc sulfide layer, respectively; performing a resist coating, photolithography, and etching process on the insulating layer in sequence, thereby forming a plurality of second trenches, wherein the second trenches are located above the first doping layer; Deposition, resist coating, photolithography and etching processes are sequentially performed in the second trench to form a first electrode layer, and a second electrode layer is deposited at the bottom of the n-type silicon layer.
9. A method for preparing a photodetector, applied to the photodetector according to any one of claims 1 to 2 and 4, characterized in that: The steps include: Providing a silicon substrate, wherein the silicon substrate comprises an n-type silicon layer and a p-type silicon layer stacked in sequence from bottom to top; performing oxide layer deposition, resist coating, photolithography and ion implantation processes on the p-type silicon layer in sequence, thereby forming a first doping layer; performing insulating layer deposition, resist coating, photolithography, and etching processes on the p-type silicon layer in sequence, thereby forming an insulating layer having a first trench; Spin-coating a molybdenum disulfide precursor solution and a zinc sulfide precursor solution in sequence at the first groove to form a molybdenum disulfide layer and a zinc sulfide layer, respectively; Deposition, coating, photolithography and etching processes are sequentially performed on the insulating layer and the functional layer to form a first electrode layer, and a second electrode layer is deposited at the bottom of the n-type silicon layer.
10. A method for preparing a photodetector, applied to the photodetector according to any one of claims 1 to 2 and 5, characterized in that: The steps include: Providing a silicon substrate, wherein the silicon substrate comprises an n-type silicon layer and a p-type silicon layer stacked in sequence from bottom to top; performing oxide layer deposition, resist coating, photolithography and ion implantation processes on the p-type silicon layer in sequence, thereby forming a first doping layer; performing insulating layer deposition, resist coating, photolithography, and etching processes on the p-type silicon layer in sequence, thereby forming an insulating layer having a first trench; Spin-coating a molybdenum disulfide precursor solution and a zinc sulfide precursor solution in sequence at the first groove to form a molybdenum disulfide layer and a zinc sulfide layer, respectively; performing a resist coating, photolithography, and etching process on the insulating layer in sequence, thereby forming a plurality of second trenches, wherein the second trenches are located above the first doping layer; Deposition, resist coating, photolithography and etching processes are sequentially performed in different second grooves to form a first electrode layer and a second electrode layer respectively.
11. A method for preparing a photodetector, applied to the photodetector according to any one of claims 1 to 2 and 6, characterized in that: The steps include: Providing a silicon substrate, wherein the silicon substrate comprises an n-type silicon layer and a p-type silicon layer stacked in sequence from bottom to top; performing oxide layer deposition, resist coating, photolithography and ion implantation processes on the p-type silicon layer in sequence, thereby forming a first doping layer; performing insulating layer deposition, resist coating, photolithography, and etching processes on the p-type silicon layer in sequence, thereby forming an insulating layer having a first trench; Spin-coating a molybdenum disulfide precursor solution and a zinc sulfide precursor solution in sequence at the first groove to form a molybdenum disulfide layer and a zinc sulfide layer, respectively; performing a resist coating, photolithography, and etching process on the insulating layer in sequence, thereby forming a plurality of second trenches, wherein the second trenches are located above the first doping layer; performing deposition, resist coating, photolithography, and etching processes in sequence in the second trench to form a first electrode layer; Deposition, resist coating, photolithography and etching processes are sequentially performed on the insulating layer and the functional layer to form a second electrode layer.
12. A method for preparing a photodetector, applied to the photodetector according to any one of claims 1 to 2 and 7, characterized in that: The steps include: Providing a silicon substrate, the silicon substrate comprising an n-type silicon layer and a p-type silicon layer stacked sequentially from bottom to top, wherein a second doping layer is provided on top of the n-type silicon layer; depositing a molybdenum disulfide layer, a zinc sulfide layer, and an ITO layer in sequence on the p-type silicon layer; Etching the bottom of the n-type silicon layer to form a deep silicon trench with an opening facing downward and arranged corresponding to the second doped layer; Filling the deep silicon trench with an electrode material to form an electrode layer, wherein the bottom of the electrode layer protrudes out of the deep silicon trench; An insulating layer is deposited on the bottom of the n-type silicon layer.