A heat-sensitive film, an infrared detector and a preparation method of the infrared detector

Abstract

The application relates to the technical field of heat-sensitive materials and infrared detection, and discloses a heat-sensitive film, an infrared detector and a preparation method of the infrared detector. x The heat-sensitive film has a resistance temperature coefficient (TCR) of up to 3.1% / K, which is higher than that of traditional vanadium oxide and amorphous silicon heat-sensitive films, can improve the signal response intensity of a device containing the heat-sensitive film, and improves the performance of the device.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of heat-sensitive materials and infrared detection, and particularly relates to a heat-sensitive film, an infrared detector and a preparation method of the infrared detector. BACKGROUND

[0002] The types of non-cooled infrared detectors mainly include Golay tubes, thermoelectric piles, pyroelectric detectors and microbolometers (also known as heat-sensitive resistor detectors). When the infrared absorption capacity of the heat-sensitive material of the heat-sensitive resistor detector is weak, an infrared absorption layer needs to be prepared on the heat-sensitive layer. At this time, the working principle is that the infrared absorption layer absorbs infrared rays, heats itself, then conducts heat to the heat-sensitive layer, and further heats the heat-sensitive layer to make it generate resistance change, and the resistance change value, i.e. the infrared radiation signal, is read out through a circuit. As can be seen, the performance (resistance temperature coefficient) of the heat-sensitive layer has a great influence on the performance of the infrared detector. However, the heat-sensitive layer material of the existing non-cooled infrared detector mainly adopts vanadium oxide or polycrystalline silicon, and the resistance temperature coefficient is still relatively low. How to further improve the resistance temperature coefficient of the heat-sensitive layer is of great significance to improve the signal response strength and other performances of the infrared detector.

[0003] Therefore, the prior art still needs to be improved and developed. SUMMARY

[0004] In view of the deficiencies of the prior art, the purpose of the present application is to provide a heat-sensitive film, an infrared detector and a preparation method of the infrared detector, aiming to solve the problem of low resistance temperature coefficient of the heat-sensitive layer material of the existing infrared detector.

[0005] The technical scheme of the present application is as follows:

[0006] In the first aspect of the present application, a heat-sensitive film is provided, wherein the heat-sensitive film comprises SnSe x particles, wherein x = 1-2.

[0007] Optionally, the thickness of the heat-sensitive film is 0.1-5 μm, and the resistance of the heat-sensitive film is 500 Ω-5 MΩ.

[0008] In the second aspect of the present application, an infrared detector is provided, wherein the infrared detector comprises a substrate, an electrode, a heat-sensitive layer and an infrared absorption layer which are sequentially stacked, and the heat-sensitive layer is the heat-sensitive film as described above.

[0009] Optionally, the infrared absorption layer adopts at least one of nanosheet infrared absorption material, nanowire infrared absorption material, nanotube infrared absorption material, nanocolumn infrared absorption material; wherein the two-dimensional plane direction of the nanosheet infrared absorption material is perpendicular to the thermal sensitive layer, the axial direction of the nanowire infrared absorption material, nanotube infrared absorption material, nanocolumn infrared absorption material is perpendicular to the thermal sensitive layer.

[0010] Optionally, the thickness of the infrared absorption layer is 0.2-10 μm.

[0011] And / or, in the direction perpendicular to the two-dimensional plane of the nanosheet infrared absorption material, the thickness of the nanosheet infrared absorption material is 25-60 nm.

[0012] Optionally, the nanosheet infrared absorption material is selected from SnSe y nanosheet, cuprous sulfide nanosheet, cuprous selenide nanosheet, wherein y=1-4.

[0013] In a third aspect, the present application provides a preparation method of the infrared detector of the present application, wherein the method comprises the following steps:

[0014] providing a substrate;

[0015] forming an electrode on the substrate;

[0016] forming a thermal sensitive layer on the electrode; the thermal sensitive layer is the thermal sensitive film, and the thermal sensitive film comprises SnSe x particles, wherein x=1-2;

[0017] forming an infrared absorption layer on the thermal sensitive layer.

[0018] Optionally, the thermal sensitive layer is formed on the electrode by epitaxial growth method; the infrared absorption layer is formed on the thermal sensitive layer by epitaxial growth method.

[0019] Optionally, the thermal sensitive layer is formed on the electrode by molecular beam epitaxial growth method, wherein the process parameters are as follows: the heating temperature of the substrate is 150-280 ℃, the heating temperature of the Sn source is 900-1300 ℃, the heating temperature of the Se source is 220-280 ℃, and the reaction time is 1-100 min.

[0020] Optionally, the infrared absorption layer is formed on the thermal sensitive layer by molecular beam epitaxial growth method, wherein when the infrared absorption layer adopts SnSe y nanosheet, the process parameters are as follows: the heating temperature of the substrate is 150-280 ℃, the heating temperature of the Sn source is 900-1300 ℃, the heating temperature of the Se source is 220-280 ℃, and the reaction time is 1-100 min.

[0021] Beneficial effects: The thermal sensitive film provided by the application has a resistance temperature coefficient (TCR) of up to 3.1% / K, which is higher than that of traditional vanadium oxide and amorphous silicon thermal sensitive films, and can improve the signal response intensity of a device containing the thermal sensitive film and improve the performance of the device. BRIEF DESCRIPTION OF DRAWINGS

[0022] Figure 1 It is a cross-sectional structure schematic diagram of an infrared detector in an embodiment of the application.

[0023] Figure 2 It is a preparation flow schematic diagram of an infrared detector in an embodiment of the application.

[0024] Figure 3 It is a preparation flow schematic diagram of an infrared detector in another embodiment of the application.

[0025] Figure 4 It is a SnSe y nanoplate infrared absorption layer prepared in embodiment 1 of the application.

[0026] Figure 5 It is a SnSe y nanoplate infrared absorption layer (wherein y=1.80) prepared in embodiment 1 of the application.

[0027] Figure 6 It is a SnSe y nanoplate infrared absorption layer (wherein y=1.80) prepared in embodiment 1 of the application.

[0028] Figure 7 It is a SnSe y nanoplate infrared absorption layer with different y values prepared in embodiment 1 of the application.

[0029] Figure 8 It is a structure schematic diagram of an interdigital electrode in embodiment 2 of the application.

[0030] Figure 9 It is a SnSe x thermal sensitive layer (wherein x=1.3) prepared in embodiment 2 of the application.

[0031] Figure 10 It is a signal response diagram of an infrared detector prepared in embodiment 2 of the application under 2W infrared light irradiation. DETAILED DESCRIPTION

[0032] The present application provides a kind of heat-sensitive film, infrared detector and the preparation method of infrared detector, to make the purpose, technical scheme and effect of the present application more clear, explicit, the following is further detailed to the present application.It should be understood that the specific embodiments described herein are only used to explain the present application, and are not intended to limit the present application.

[0033] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used in the description of the application herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the application.

[0034] The present application provides a kind of heat-sensitive film, infrared detector and the preparation method of infrared detector, to make the purpose, technical scheme and effect of the present application more clear, explicit, the following is further detailed to the present application.It should be understood that the specific embodiments described herein are only used to explain the present application, and are not intended to limit the present application. x The present application provides a kind of heat-sensitive film, infrared detector and the preparation method of infrared detector, to make the purpose, technical scheme and effect of the present application more clear, explicit, the following is further detailed to the present application.It should be understood that the specific embodiments described herein are only used to explain the present application, and are not intended to limit the present application.

[0035] In the embodiment, the resistance temperature coefficient (TCR) of the heat-sensitive film is up to 3.1% / K, and the x value is 1.3 at this time, corresponding to more defects in the heat-sensitive film, resulting in a larger carrier concentration generated by heating, and a higher resistance temperature coefficient. With further increase of the x value, i.e. further increase of the Se / Sn atomic ratio, the carrier concentration in the heat-sensitive film decreases, and the resistance temperature coefficient decreases.

[0036] In an embodiment, the heat-sensitive film is composed of SnSe x particles, wherein x=1-2. The heat-sensitive film is composed of dense SnSe x particles, which can be spherical particles, rod-shaped particles, etc.

[0037] In an embodiment, the thickness of the heat-sensitive film is 0.1-5 μm. The heat-sensitive film with the thickness in this range can improve the resistance change speed of itself, and further improve the response speed of the device. For example, the thickness of the heat-sensitive film can be 0.1 μm, 0.2 μm, 0.5 μm, 1 μm, 2 μm, 3 μm, 4 μm or 5 μm, etc.

[0038] In an embodiment, the resistance of the heat-sensitive film is 500 Ω-5 MΩ.

[0039] The present application also provides a preparation method of the heat-sensitive film as described above in the embodiments of the present application, which comprises the following steps:

[0040] The heat-sensitive thin film is formed by a molecular beam epitaxy growth method, and the process parameters are as follows: the heating temperature of the substrate is 150-280℃, the heating temperature of the Sn source is 900-1300℃, the heating temperature of the Se source is 220-280℃, and the reaction time is 1-100min. In this embodiment, the heat-sensitive thin film can be prepared on any substrate surface where the heat-sensitive thin film is needed by using the molecular beam epitaxy growth method.

[0041] The embodiment of the present application further provides an infrared detector, which comprises, as shown in the figure, a substrate 1, an electrode 2, a heat-sensitive layer 3 and an infrared absorption layer 4 which are sequentially stacked, and the heat-sensitive layer 3 is the heat-sensitive thin film as described above. Figure 1

[0042] In the embodiment of the present application, the temperature coefficient of resistance (TCR) of the heat-sensitive layer is as high as 3.1% / K, which is higher than that of the conventional vanadium oxide and amorphous silicon heat-sensitive layer, so that the signal response intensity of the infrared detector can be improved, and the performance of the infrared detector can be improved.

[0043] In the embodiment, the heat-sensitive layer is the heat-sensitive thin film as described above, i.e., the heat-sensitive layer is composed of dense SnSe x particles, and x=1-2.

[0044] Further, the thickness of the heat-sensitive layer is 0.1-5μm, and the heat-sensitive layer with the thickness can improve the resistance change speed of the heat-sensitive layer, so that the response speed of the infrared detector can be further improved. For example, the thickness of the heat-sensitive layer can be 0.1μm, 0.2μm, 0.5μm, 1μm, 2μm, 3μm, 4μm or 5μm, etc.

[0045] In an embodiment, the infrared absorption layer comprises at least one of, but is not limited to, a nano-sheet infrared absorption material, a nano-wire infrared absorption material, a nano-tube infrared absorption material and a nano-column infrared absorption material; the two-dimensional plane direction of the nano-sheet infrared absorption material is perpendicular to the heat-sensitive layer, and the axial direction of the nano-wire infrared absorption material, the nano-tube infrared absorption material and the nano-column infrared absorption material is perpendicular to the heat-sensitive layer.

[0046] In the embodiment, the infrared absorption layer composed of a plurality of nano-sheet infrared absorption materials with the two-dimensional plane direction perpendicular to the heat-sensitive layer has a physical light trapping structure, and the extinction effect can be achieved through the gap between the sheets.

[0047] In an embodiment, the thickness of the infrared absorption layer is 0.2-10μm, so that the infrared absorption layer can have good infrared absorption capacity.

[0048] ​In an embodiment, the thickness of the nanosheet-shaped infrared absorption material is 25-60 nm in the direction perpendicular to the two-dimensional plane of the nanosheet-shaped infrared absorption material. For example, it can be 25 nm, 30 nm, 35 nm, 40 nm, 45 nm, 50 nm, 55 nm or 60 nm, etc.

[0049] In an embodiment, the nanosheet-shaped infrared absorption material is selected from SnSe y at least one of the nanosheet, cuprous sulfide nanosheet, cuprous selenide nanosheet, wherein y = 1-4.

[0050] In this embodiment, the nanosheet-shaped infrared absorption material is selected from SnSe y When the nanosheet is SnSe y The content of Sn in the nanosheet increases, the metalization is enhanced, the resistance is reduced, and the infrared absorption capacity is enhanced.

[0051] Further, the SnSe y nanosheet in the infrared absorption layer can be in contact with the SnSe y nanosheet, forming a certain angle, thereby forming a gap between the nanosheets. The SnSe y nanosheet has a thickness of 25-60 nm, and the SnSe y nanosheet has a height of 0.2-10 μm in the direction perpendicular to the thermosensitive layer, so that the SnSe y nanosheet has stronger infrared absorption capacity.

[0052] In order to better realize the light trapping structure of the SnSe y nanosheet perpendicular to the thermosensitive layer, in an embodiment, the infrared detector further comprises a reflective layer disposed between the substrate and the electrode. Further, the infrared detector further comprises an insulating film disposed between the reflective layer and the electrode.

[0053] In this embodiment, the reflective layer can be formed by evaporation including but not limited to gold, silver, titanium, etc.

[0054] The traditional non-cooled infrared detector mainly relies on vanadium oxide or polysilicon material as a thermal sensitive layer, but the infrared absorption capacity of the above-mentioned materials is weak, so it is necessary to prepare an infrared absorption layer or use a resonant cavity structure to perform infrared absorption. The working principle of the infrared absorption layer is to heat the thermal sensitive layer by conducting heat to the thermal sensitive layer after absorbing infrared rays, so as to heat the thermal sensitive layer to generate resistance change. At present, the infrared absorption layer is mostly a multilayer structure, and an insulating layer needs to be prepared on the thermal sensitive layer to prevent circuit short circuit. The thermal conductivity of the additional insulating layer will seriously affect the sensitivity and response time of the detector, and multiple processes are needed to achieve it, which increases the production cost. The resonant cavity structure has the problems of narrow infrared absorption band and complex preparation process, the former will reduce the detection sensitivity of the detector, and the latter will often result in huge product cost. Based on this, the embodiment of the present application also provides a preparation method of the infrared detector as described above. Figure 2 as shown in the embodiment of the present application, comprising the steps of:

[0055] S1, providing a substrate;

[0056] S2, forming an electrode on the substrate;

[0057] S3, forming a thermal sensitive layer on the electrode; the thermal sensitive layer is the thermal sensitive film, and the thermal sensitive film comprises SnSe x particles, wherein x = 1-2;

[0058] S4, forming an infrared absorption layer on the thermal sensitive layer.

[0059] The preparation method provided by the embodiment of the present application is simple, low in cost, and can prepare a non-cooled infrared detector with high response speed and sensitivity. Specifically, the infrared absorption layer is directly prepared on the thermal sensitive layer in the embodiment of the present application, which greatly reduces the preparation difficulty, and the structure that the infrared absorption layer is in direct contact with the thermal sensitive layer can conduct all the heat generated by the infrared absorption layer absorbing infrared light to the thermal sensitive layer, reduce heat loss, save the time needed to heat the insulating layer in the prior art, and further improve the response speed and sensitivity of the detector. Further, the thermal sensitive layer has a high temperature coefficient of resistance, which can further improve the signal response strength of the infrared detector.

[0060] In step S1, in an embodiment, the substrate is a rigid substrate or a flexible substrate, wherein the rigid substrate includes but is not limited to a silicon substrate, and the flexible substrate includes but is not limited to a polyimide substrate. In this embodiment, the rigid substrate or the flexible substrate can be selected according to different application scenarios of the infrared detector.

[0061] In step S2, the electrode includes a first electrode and a second electrode arranged oppositely. In an embodiment, the first electrode and the second electrode in interdigital structure are formed on the substrate by electron beam evaporation, and the fingers of the first electrode and the second electrode in interdigital structure cross each other. The material of the electrode is selected from at least one of chromium, gold, titanium, aluminum, nickel, but is not limited thereto. The electrode can be composed of metal layers arranged in layers, for example, the electrode can be composed of chromium layer and gold layer arranged in layers, can also be composed of titanium layer and gold layer arranged in layers, and can also be composed of nickel layer, aluminum layer and nickel layer arranged in layers.

[0062] In steps S3-S4, in an embodiment, the thermosensitive layer is formed on the electrode by epitaxial growth, and the infrared absorption layer is formed on the thermosensitive layer by epitaxial growth.

[0063] In a further embodiment, the thermosensitive layer is formed on the electrode by molecular beam epitaxy, wherein the process parameters used are: the heating temperature of the substrate is 150-280°C (for example, it can be 150°C, 160°C, 170°C, 180°C, 200°C, 220°C, 240°C, 260°C or 280°C, etc.), the heating temperature of the Sn source is 900-1300°C (for example, it can be 900°C, 1000°C, 1100°C, 1200°C or 1300°C, etc.), the heating temperature of the Se source is 220-280°C (for example, it can be 220°C, 230°C, 240°C, 250°C, 260°C, 270°C or 280°C, etc.), and the reaction time is 1-100 min (for example, it can be 1 min, 5 min, 10 min, 20 min, 30 min, 40 min, 50 min, 60 min, 70 min, 80 min, 90 min or 100 min, etc.); the infrared absorption layer is formed on the thermosensitive layer by molecular beam epitaxy, wherein when the infrared absorption layer uses SnSe yWhen the nanosheet is adopted, the process parameters are as follows: the heating temperature of the substrate is 150-280°C (for example, it can be 150°C, 160°C, 170°C, 180°C, 200°C, 220°C, 240°C, 260°C, or 280°C, etc.), the heating temperature of the Sn source is 900-1300°C (for example, it can be 900°C, 1000°C, 1100°C, 1200°C, or 1300°C, etc.), the heating temperature of the Se source is 220-280°C (for example, it can be 220°C, 230°C, 240°C, 250°C, 260°C, 270°C, or 280°C, etc.), and the reaction time is 1-100 min (for example, it can be 1 min, 5 min, 10 min, 20 min, 30 min, 40 min, 50 min, 60 min, 70 min, 80 min, 90 min, or 100 min, etc.). It can be understood that, in step S3, when the thermosensitive layer is formed on the electrode by the molecular beam epitaxy growth method, the heating temperature of the substrate is the heating temperature of the base and the electrode formed on the surface of the base as a whole, that is, the substrate in step S3 is the base on which the electrode is formed; in step S4, when the infrared absorption layer is formed on the thermosensitive layer by the molecular beam epitaxy growth method, the heating temperature of the substrate is the heating temperature of the base, the electrode, and the thermosensitive layer formed on the base as a whole, that is, the substrate in step S4 is the base on which the electrode and the thermosensitive layer are sequentially formed. y The substrate when the nanosheet is adopted is the base on which the electrode and the thermosensitive layer are sequentially formed.

[0064] The existing preparation methods of infrared absorption materials, such as laminated thin film structure infrared absorption materials (for example, two or more of a Si3N4 layer, a SiO2 layer, a TiO2 layer, an amorphous silicon layer, and a TiN layer are used as a laminated thin film structure) and surface micro-nano processing prepared infrared absorption materials (for example, a surface microstructure is realized by performing surface micro-nano processing on the infrared absorption material by a photolithography method or the like, so that infrared waves are absorbed), all have the problem of requiring multiple preparation steps in the process, which is difficult to realize in engineering, and the micro-nano processing prepared infrared absorption materials have difficult-to-solve problems in the process and product cost. In the present embodiment (steps S3-S4), based on the co-evaporation means, the molecular beam epitaxy growth method is adopted to realize one-step preparation of the thermosensitive layer and the infrared absorption layer (specifically, SnSe x The particle thin film forms the thermosensitive layer, and SnSe y The nanosheet forms the infrared absorption layer, and SnSe y The nanosheet is vertically grown on SnSe xThe infrared absorption layer and the thermal sensitive layer are directly contacted, heat generated by the infrared absorption layer absorbing infrared light can be completely conducted to the thermal sensitive layer, heat loss is reduced, time required for heating the insulating layer is saved, and the response speed and sensitivity of the detector are further improved.

[0065] In addition, compared with the design that the resonant cavity only absorbs infrared light of a certain wavelength in the prior art, in the embodiment, the infrared absorption layer adopts SnSe y The nanosheet can realize absorption of infrared light in a 2-25 mu m wave band, and greatly improves the sensitivity of the infrared detector.

[0066] In steps S3 and S4, the thermal sensitive layer and the infrared light absorption layer can be prepared in a molecular beam epitaxy device, wherein the vacuum degree of the chamber is controlled to be 1*10 -5 ~ 9*10 -4 Pa.

[0067] In step S4, the infrared absorption capacity of the infrared absorption layer including the SnSe y nanosheet can be regulated by regulating the heating temperature of the substrate, the heating temperature of the Sn source, the heating temperature of the Se source and the reaction time.

[0068] Specifically, the infrared absorption capacity can be improved by reducing the heating temperature of Se, so that the content of Sn in the compound is increased; the content of Sn in the compound can be increased by regulating the opening time of the Sn source and the Se source, that is, the Sn source is opened for 0.2-5 min first, and then the Se source is opened for reaction, so that the content of Sn in the compound is increased, and the infrared absorption capacity is further improved; the heating temperature of the substrate can be regulated, the heating temperature and the heating time of the substrate are reduced, and the content of Sn in the compound is increased, so that the infrared absorption capacity is improved.

[0069] In a specific embodiment of the present application, as shown in Figure 3 a preparation method of an integrated infrared detector is provided, comprising the following steps:

[0070] S11, providing a substrate;

[0071] S21, forming an electrode with an interdigital structure on the substrate by an electron beam evaporation method;

[0072] S31, growing SnSe xThe particles form a thermal sensitive layer, wherein x = 1-2, and the process parameters used are: the heating temperature of the substrate is 150-280℃, the heating temperature of the Sn source is 900-1300℃, the heating temperature of the Se source is 220-280℃, and the reaction time is 1-100 min;

[0073] S41, growing SnSe on the thermal sensitive layer by a molecular beam epitaxy growth method y The nanosheets form an infrared absorption layer, and the SnSe y The two-dimensional plane direction of the nanosheets is perpendicular to the thermal sensitive layer, wherein y = 1-4, and the process parameters used are: the heating temperature of the substrate is 150-280℃, the heating temperature of the Sn source is 900-1300℃, the heating temperature of the Se source is 220-280℃, and the reaction time is 1-100 min.

[0074] In this embodiment, the same raw materials are used to realize one-step preparation of the thermal sensitive layer and the infrared absorption layer (specifically SnSe y The particle thin film forms a thermal sensitive layer, and the SnSe y The nanosheets form an infrared absorption layer), thereby obtaining an integrated infrared detector. In this way, the existing multilayer film preparation process and surface micro-nano structure processing process are replaced, the processes and photolithography processes required for preparing different materials are omitted, the complex and high-cost production process is avoided, and finally the preparation of low-cost products is realized. At the same time, the structure that the infrared absorption layer directly contacts the thermal sensitive layer can conduct all the heat generated by the infrared absorption layer absorbing infrared light to the thermal sensitive layer, reduce the heat loss, save the time required for heating the insulating layer, and further improve the response speed and sensitivity of the infrared detector.

[0075] The following will be described in detail through specific embodiments.

[0076] Embodiment 1

[0077] In a molecular beam epitaxy device, SnSe y nanosheet infrared absorption layer 21, a structural schematic diagram thereof is as Figure 4 shown in FIG. 1;

[0078] (1) SnSe y nanosheet infrared absorption layer with y value of 1.80 is prepared, and the process parameters used are: the chamber vacuum degree needs to be controlled at 9x10 -4 Pa, the substrate temperature is 260℃, the temperature of the Sn source is 1140℃, the temperature of the Se source is 160℃, after the temperature parameters are correct, the shutters of the sources are opened at the same time, the reaction time is 30 min, and SnSe ynanoplate infrared absorption layer, wherein y = 1.80. The infrared absorption spectrum thereof is shown in Figure 5 As shown, the SnSe y The absorption band of the nanoplate infrared absorption layer can cover 2.5-25 μm, and the absorption rate thereof at 2.5-5 μm reaches nearly 90%, and the absorption rate thereof at 5-25 μm is also more than 80%. SnSe y The SEM image of the surface of the nanoplate infrared absorption layer is shown in Figure 6 As shown, (a) is the SEM image of the surface of the SnSe y The SEM image of the surface of the nanoplate infrared absorption layer is shown in y The SEM image of the cross section of the nanoplate infrared absorption layer is shown in

[0079] (2) SnSe y nanoplate infrared absorption layer with y = 1.81 was prepared, and the process parameters used were as follows: the chamber vacuum degree needed to be controlled at 9 × 10 -4 Pa, the substrate temperature was 205℃, the temperature of the Sn source was 1195℃, the temperature of the Se source was 255.5℃, after the temperature parameters were correct, the shutters of the sources were opened at the same time, and the reaction time was 30 min, thereby obtaining the SnSe y nanoplate infrared absorption layer with y = 1.81;

[0080] (3) SnSe y nanoplate infrared absorption layer with y = 1.959 was prepared, and the process parameters used were as follows: the chamber vacuum degree needed to be controlled at 9 × 10 -4 Pa, the substrate temperature was 205℃, the temperature of the Sn source was 1195℃, the temperature of the Se source was 257.5℃, after the temperature parameters were correct, the shutters of the sources were opened at the same time, and the reaction time was 30 min, thereby obtaining the SnSe y nanoplate infrared absorption layer with y = 1.959;

[0081] (4) SnSe y nanoplate infrared absorption layer with y = 2.18 was prepared, and the process parameters used were as follows: the chamber vacuum degree needed to be controlled at 9 × 10 -4 Pa, the substrate temperature was 205℃, the temperature of the Sn source was 1195℃, the temperature of the Se source was 260℃, after the temperature parameters were correct, the shutters of the sources were opened at the same time, and the reaction time was 30 min, thereby obtaining the SnSe y nanoplate infrared absorption layer with y = 2.18;

[0082] (5) SnSe y nanoplate infrared absorption layer with y = 2.75 was prepared, and the process parameters used were as follows: the chamber vacuum degree needed to be controlled at 9 × 10 -4Pa, the temperature of the Sn source was 1140℃, the temperature of the Se source was 250℃, after each temperature parameter was correct, the shutters of each source were opened at the same time, and the reaction time was 30 min, to prepare SnSe y nanoplatelet infrared absorption layer, wherein y=2.75;

[0083] SnSe with y being 1.81, 1.959, 2.11 and 2.75, which was perpendicular to the silicon substrate, was prepared by (2)-(4) respectively y The infrared absorption spectrum test was performed on the nanoplatelet infrared absorption layer, and the results are shown in Figure 7 As can be seen from the figure, with the increase of y, the infrared absorption capacity shows a weakening trend.

[0084] Example 2

[0085] The preparation method of the integrated infrared detector comprises the following steps:

[0086] On the polyimide substrate, a Cr layer and an Au layer were evaporated in sequence by using an electron beam evaporation method to prepare interdigital electrodes (a structure diagram of the interdigital electrodes is shown in Figure 8 The interdigital electrodes are composed of the laminated Cr layer and Au layer, the thickness of the Cr layer is 20 nm, the thickness of the Au layer is 100 nm, and the Cr layer is attached to the polyimide substrate;

[0087] In a molecular beam epitaxy device, SnSe x particles were grown on the interdigital electrodes by a molecular beam epitaxy growth method to form a thermosensitive layer (x=1.3), wherein the process parameters used are: the chamber vacuum degree needs to be controlled at 9x10 -4 Pa, the temperature of the Sn source was 1185℃, the temperature of the Se source was 225℃, after each temperature parameter was correct, the shutters of each source were opened at the same time, and the reaction time was 30 min, to prepare the thermosensitive layer (i.e. SnSe x thermosensitive layer, x=1.3); the SEM diagram is shown in Figure 9 The SEM diagram of the surface of the SnSe x thermosensitive layer, and (b) is the SEM diagram of the surface of the SnSe x thermosensitive layer.

[0088] In a molecular beam epitaxy device, an infrared absorption layer was prepared on the thermosensitive layer by using a molecular beam epitaxy growth method, the infrared absorption layer was composed of SnSe y nanoplatelets (y=1.3) perpendicular to the thermosensitive layer, wherein the process parameters used are: the chamber vacuum degree needs to be controlled at 9x10 -4Pa, the substrate temperature is 190 DEG C, the temperature of the Sn source is 1185 DEG C, the temperature of the Se source is 250 DEG C, after each temperature parameter is correct, the shutters of each source are opened at the same time, the reaction time is 30 min, and SnSe is prepared y The nanosheet infrared absorption layer (y=1.3) is prepared.

[0089] The prepared red light detector is irradiated by a 2W infrared lamp, and the current response result is as shown in Figure 10 .

[0090] In summary, the application provides a thermosensitive film, an infrared detector and a preparation method of the infrared detector. The resistance temperature coefficient (TCR) of the thermosensitive film is as high as 3.1% / K, which is higher than that of traditional vanadium oxide and amorphous silicon thermosensitive films, can improve the signal response intensity of a device containing the thermosensitive film, and improve the performance of the device. The preparation method of the infrared detector is simple and low in cost, the infrared absorption layer is directly prepared on the thermosensitive layer, which greatly reduces the preparation difficulty, and the structure that the infrared absorption layer is directly in contact with the thermosensitive layer can conduct all the heat generated by the infrared absorption layer absorbing infrared light to the thermosensitive layer, reduces the heat loss, saves the time required for heating the insulating layer in the prior art, and further improves the response speed and sensitivity of the detector.

[0091] It should be understood that the application of the application is not limited to the above examples, and those skilled in the art can improve or change according to the above description, and all these improvements and changes should belong to the protection scope of the appended claims of the application.

Claims

1. A method for fabricating an integrated infrared detector, characterized in that, The method comprises the steps of: providing a substrate; forming an electrode on the substrate; A heat-sensitive layer is formed on the electrode by a molecular beam epitaxy growth method, and SnSe is formed on the heat-sensitive layer in a two-dimensional plane direction perpendicular to the heat-sensitive layer y Nanoplatelets, y = 1-4, resulting in an infrared absorption layer; The heat-sensitive layer is a heat-sensitive film, and the heat-sensitive film comprises SnSe x The particle, wherein x=1-2; and the process parameters for forming the heat-sensitive layer on the electrode are as follows: the heating temperature of the substrate is 150-280 ℃, the heating temperature of the Sn source is 900-1300 ℃, the heating temperature of the Se source is 220-280 ℃, and the reaction time is 1-100 min. forming SnSe on the heat-sensitive layer in a two-dimensional planar direction perpendicular to the heat-sensitive layer y The process parameters for the nanosheet are as follows: the heating temperature of the substrate is 150-280℃, the heating temperature of the Sn source is 900-1300℃, the heating temperature of the Se source is 220-280℃, and the reaction time is 1-100min.

2. The production method according to claim 1, characterized by, the thickness of the thermosensitive film is 0.1-5 μm, and the resistance of the thermosensitive film is 500 Ω-5 MΩ.

3. The preparation method according to claim 1, characterized in that, the SnSe y The thickness of the nanosheet is 25 to 60 nm, and the SnSe y The height of the nanosheet in a direction perpendicular to the heat- sensitive layer is 0.2 to 10 μm.

4. The method of claim 1, wherein, The substrate is a rigid substrate or a flexible substrate.

5. The preparation method according to claim 1, characterized in that, The electrode comprises oppositely arranged first and second electrodes, and the first and second electrodes are in an interdigital structure.

6. The preparation method according to claim 5, characterized in that, The first and second electrodes in an interdigital structure are formed on the substrate by an electron beam evaporation method.

7. An integrated infrared detector, characterized by The integrated infrared detector comprises a substrate, an electrode, a thermosensitive layer and an infrared absorption layer which are sequentially stacked, and is prepared by the preparation method of any one of claims 1-6.

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