A flexible near-infrared II region photodetector based on two-dimensional material nanoribbons

Abstract

A flexible near-infrared II region photodetector based on two-dimensional material nanoribbons relates to the technical field of optoelectronic devices, and solves the problems of poor flexibility and low responsivity of existing near-infrared II region photodetectors. It includes: a flexible substrate; an inorganic nanoribbon array disposed on the upper surface of the flexible substrate; a metal electrode disposed on the upper surface of the inorganic nanoribbon array; an organic modification layer connecting the inorganic nanoribbon array, and the near-infrared II region spectral absorption rate of the organic modification layer is not lower than that of methylene blue, porphyrin compounds or indocyanine green in the near-infrared II region. The preparation method is: preparing an inorganic nanoribbon array on the flexible substrate; preparing an organic modification layer on the inorganic nanoribbon array. The present invention improves the optoelectronic conversion efficiency of the device through the energy band distribution and coupling between two-dimensional organic and inorganic materials; improves the responsivity of the device in the near-infrared II region; can be attached to the surface of a living body for real-time detection of a moving living body.

Description

Technical Field

[0001] The present invention relates to the technical field of near-infrared II region photodetectors, and particularly relates to a flexible near-infrared II region photodetector based on two-dimensional material nanoribbons. Background Art

[0002] Near-infrared light detection plays an important role in fields such as information communication, meteorological observation, and medical imaging. Among them, the near-infrared II region band (1000 - 1700 nm) has the advantages of strong skin penetration ability and low energy. Compared with traditional ultrasonic imaging, near-infrared II region imaging has higher resolution and lower harm to organisms, and can be used for blood vessel, organ, and in vivo imaging of organisms. It has been the research focus in the fields of biology and medical imaging in recent years. However, the fluorescence in the near-infrared II region is weak, and the fluorescence efficiency will further decay after passing through the body surface. Most of the currently commercial infrared detectors are based on inorganic materials such as indium gallium arsenide, and the responsivity is not high (about 1 A / W). And in practical applications, it is often necessary to perform long-term target detection and imaging on moving organisms, and it is necessary to attach the fluorescence signal detector to the surface of the organism for real-time detection. The materials used in traditional near-infrared II region detectors are III-V group bulk materials. Due to the limitations of their own properties and processing technology, these materials have poor mechanical flexibility and are difficult to attach to the surface of organisms to achieve real-time detection of moving organisms. Summary of the Invention

[0003] In order to solve the problems of poor flexibility and low responsivity of existing near-infrared II region photodetectors, the present invention provides a flexible near-infrared II region photodetector based on two-dimensional material nanoribbons.

[0004] The technical solutions adopted by the present invention to solve the technical problems are as follows:

[0005] A flexible near-infrared II region photodetector based on two-dimensional material nanoribbons, comprising:

[0006] A flexible substrate;

[0007] An inorganic nanoribbon array disposed on the upper surface of the flexible substrate;

[0008] A metal electrode disposed on the upper surface of the inorganic nanoribbon array;

[0009] An organic modification layer, the organic modification layer is disposed on the inorganic nanoribbon array and / or in the gaps of the inorganic nanoribbon array, the organic modification layer connects the inorganic nanoribbon array, and the near-infrared II region spectral absorption rate of the organic modification layer is not lower than that of methylene blue, porphyrin compounds or indocyanine green in the near-infrared II region.

[0010] A preparation method of a flexible photodetector in the second near-infrared region based on two-dimensional material nanoribbons, characterized by comprising the following steps:

[0011] S1. Prepare an inorganic nanoribbon array on a flexible substrate;

[0012] S2. Prepare a metal electrode on the inorganic nanoribbon array;

[0013] S3. Prepare an organic modification layer on the upper surface of the flexible substrate and / or on the upper surface of the inorganic nanoribbon array.

[0014] The beneficial effects of the present invention are as follows:

[0015] The flexible photodetector and preparation method in the second near-infrared region based on two-dimensional material nanoribbons of the present invention achieve light detection in the second near-infrared region based on an inorganic nanoribbon array and an organic modification layer. Using highly conductive two-dimensional inorganic nanoribbons modified with organic molecules as the light-responsive material can improve the responsivity of the device in the second near-infrared region. Through the energy band distribution and coupling between two-dimensional organic and inorganic materials, the light-electricity conversion efficiency of the device is improved. The present invention improves the light absorption of the device in the second near-infrared region band through an organic molecular material, and improves the photogenerated carrier mobility of the device through highly conductive two-dimensional inorganic nanoribbons, ultimately improving the responsivity in the second near-infrared region. And by utilizing the good mechanical flexibility of two-dimensional materials and organic materials, the photoelectric detection device can be attached to the surface of a living body to detect a moving living body in real time. Description of the Drawings

[0016] Figure 1 It is a schematic structural diagram of the flexible substrate of the present invention.

[0017] Figure 2 It is a structural diagram of a graphene film in Embodiment 1 of the present invention.

[0018] Figure 3 It is a structural diagram of a graphene nanoribbon array in Embodiment 1 of the present invention.

[0019] Figure 4 It is a structural diagram of a metal electrode in Embodiment 1 of the present invention.

[0020] Figure 5 It is a structural diagram of an organic molecule in Embodiment 1 of the present invention.

[0021] Figure 6 It is a structural diagram of palladium metal in Embodiment 2 of the present invention.

[0022] Figure 7 It is a structural diagram of a palladium selenide nanoribbon array in Embodiment 2 of the present invention

[0023] Figure 8 It is a structural diagram of an organic molecule in Embodiment 2 of the present invention.

[0024] Figure 9 This is the structural diagram of the black phosphorus thin film according to the second embodiment of the present invention.

[0025] Figure 10 This is the structural diagram of the black phosphorus nanoribbon array according to the second embodiment of the present invention.

[0026] In the figure: 1. Flexible substrate, 2. Graphene thin film, 3. Graphene nanoribbon array, 4. Metal electrode, 5. Organic molecule, 6. Palladium metal, 7. Palladium selenide nanoribbon array, 8. Black phosphorus thin film, 9. Black phosphorus nanoribbon array 9. Specific embodiments

[0027] The present invention will be further described in detail below with reference to the accompanying drawings and embodiments.

[0028] A flexible near-infrared II region photodetector based on two-dimensional material nanoribbons, comprising: a flexible substrate 1, an inorganic nanoribbon array, a metal electrode 4, and an organic modification layer. Refer to Figure 5 and Figure 8 , the inorganic nanoribbon array is disposed on the upper surface of the flexible substrate 1, and the metal electrode 4 is disposed on the upper surface of the inorganic nanoribbon array. The organic modification layer is connected to the inorganic nanoribbon array. The organic modification layer can be only disposed on the inorganic nanoribbon array, that is, an organic molecule 5 is modified on the upper surface of the inorganic nanoribbon array; the organic modification layer can be only disposed in the nanoribbon gaps of the inorganic nanoribbon array, on the upper surface of the flexible substrate 1, that is, an organic molecule 5 is modified on the upper surface of the flexible substrate 1 in the gaps of the inorganic nanoribbon array. At this time, the organic modification layer is connected to the nanoribbons adjacent to it on both sides ("it" refers to the organic modification layer located between two adjacent nanoribbons); the organic modification layer can be disposed on the upper surface of the inorganic nanoribbon array and in the nanoribbon gaps of the inorganic nanoribbon array, that is, disposed on the upper surface of the flexible substrate 1 and on the upper surface of the inorganic nanoribbon array. The organic modification layer is an organic material with high absorption in the near-infrared II region band, and methylene blue, porphyrin compounds, or indocyanine green can be used. Other materials can also be used. Other materials refer to materials with a spectral absorption rate in the 1000-1700 nm band in the near-infrared II region not lower than the spectral absorption rate of methylene blue in the near-infrared II region, or materials with a spectral absorption rate in the near-infrared II region not lower than the spectral absorption rate of porphyrin compounds in the near-infrared II region, or materials with a spectral absorption rate in the near-infrared II region not lower than the spectral absorption rate of indocyanine green in the near-infrared II region.

[0029] The material of the inorganic nanobelt array is an inorganic material, and the material of the inorganic nanobelt array can be graphene, black phosphorus, palladium selenide, hafnium sulfide, platinum sulfide, tin telluride, molybdenum diselenide, etc. The width range of the nanobelts in the inorganic nanobelt array is 2 nm - 200 nm, the thickness range of the nanobelts in the inorganic nanobelt array is 1 nm - 20 nm, and the spacing range between the nanobelts in the inorganic nanobelt array is 2 nm - 200 nm.

[0030] The metal electrode 4 is located on the flexible substrate 1 and the inorganic nanobelt array. The metal electrode 4 includes a positive electrode and a negative electrode, and an organic modification layer is located between the positive electrode and the negative electrode. An organic modification layer can also be provided on the metal electrode 4. An organic modification layer can also be provided on the upper surface of the flexible substrate 1 and in the gaps between the nanobelts of the inorganic nanobelt array.

[0031] A preparation method of a flexible photodetector in the second near-infrared region based on two-dimensional material nanobelts includes the following steps:

[0032] S1. Prepare an inorganic nanobelt array on the flexible substrate 1;

[0033] S2. Prepare the metal electrode 4 on the inorganic nanobelt array;

[0034] S3. Prepare an organic modification layer on the upper surface of the flexible substrate and / or on the upper surface of the inorganic nanobelt array.

[0035] Among them, the specific process of S1 is: prepare an inorganic nanolayer on the flexible substrate 1, and etch the inorganic nanolayer to obtain an inorganic nanobelt array. The specific process of S3 can be: prepare an organic modification layer on the inorganic nanobelt array by spin coating or evaporation. The specific process of S3 can be: prepare an organic modification layer on the flexible substrate and in the gaps between the nanobelts of the inorganic nanobelt array by spin coating or evaporation. The specific process of S3 can also be: prepare an organic modification layer on the upper surface of the flexible substrate of the semi-finished product obtained in S2 and on the upper surface of the inorganic nanobelt array by spin coating or evaporation.

[0036] Several implementation modes are listed below for detailed description.

[0037] Implementation mode 1: Prepare the flexible substrate 1 as Figure 1 ; transfer the graphene thin film 2 on the flexible substrate 1 as Figure 2 ; use electron beam lithography and oxygen plasma treatment to etch to obtain the graphene nanobelt array 3 as Figure 3 , that is, the inorganic nanobelt array; use photolithography, electron beam evaporation and stripping techniques to prepare the metal electrode 4 on the graphene nanobelt array 3 as Figure 4 ; use spin coating or evaporation to modify organic molecules 5 on the graphene nanobelts as Figure 5, the organic modification layer is prepared, and a flexible photodetector in the second near-infrared region based on two-dimensional material nanoribbons is prepared. The organic molecule 5 can be an organic molecule 5 with high absorption in the second near-infrared band, such as methylene blue, porphyrin compounds, or indocyanine green. Specifically, a solution for preparing the organic modification layer is prepared, and the solution of the organic modification layer is spin-coated on Figure 4 the graphene nanoribbon array 3 described above, and heated to obtain the organic modification layer.

[0038] Embodiment 2: Prepare a flexible substrate 1; deposit one to several layers of palladium metal 6 on the flexible substrate 1 by means of sputtering, evaporation, etc., such as Figure 6 ; selenize palladium at a low temperature to obtain a palladium selenide nanoribbon array 7 such as Figure 7 , that is, an inorganic nanoribbon array; prepare a metal electrode 4 by means of photolithography, electron beam evaporation, and stripping techniques; modify the organic molecule 5 on the graphene nanoribbon by means of spin coating, evaporation coating, crystallization, etc., such as Figure 8 , the organic modification layer is prepared, and a flexible photodetector in the second near-infrared region based on two-dimensional material nanoribbons is prepared. The organic molecule 5 can be an organic molecule 5 with high absorption in the second near-infrared band, such as methylene blue, porphyrin, or indocyanine green.

[0039] Embodiment 3: Prepare a flexible substrate 1; transfer a black phosphorus thin film 8 onto the flexible substrate 1 by means of dry transfer, such as Figure 9 ; obtain a black phosphorus nanoribbon array 9 by means of reactive ion beam etching, such as Figure 10 , that is, an inorganic nanoribbon array; prepare a metal electrode 4 by means of photolithography, electron beam evaporation, and stripping techniques; modify the organic molecule 5 on the graphene nanoribbon by means of spin coating or evaporation coating, etc. The organic modification layer is prepared, and a flexible photodetector in the second near-infrared region based on two-dimensional material nanoribbons is prepared. The organic molecule 5 can be methylene blue, porphyrin, indocyanine green, etc., which are organic molecules 5 with high absorption in the second near-infrared band.

[0040] The present invention realizes near-infrared II region light detection based on two-dimensional inorganic nanoribbon arrays and organic materials. Using the organic molecule 5-modified highly conductive two-dimensional inorganic nanoribbons as the response channel to improve the responsivity of the device in the second near-infrared region. Through the energy band distribution and coupling between two-dimensional organic and inorganic materials, the optoelectronic conversion efficiency of the device is improved. The present invention improves the light absorption of the device in the second near-infrared band through the organic molecule 5 material, and improves the photogenerated carrier mobility of the device through the highly conductive two-dimensional inorganic nanoribbons, ultimately improving the responsivity in the second near-infrared region. And by utilizing the excellent mechanical flexibility of two-dimensional materials and organic materials, the optoelectronic detection device can be attached to the surface of a living body to perform real-time detection on a moving living body.

[0041] The above are only the preferred embodiments of the present invention. It should be noted that for those of ordinary skill in the art, without departing from the principle of the present invention, several improvements and modifications can be made, and these improvements and modifications should also be regarded as the protection scope of the present invention.

Claims

1. A flexible near-infrared II-region photodetector based on two-dimensional material nanoribbons, characterized in that Comprising: A flexible substrate; An inorganic nanobelt array disposed on the upper surface of the flexible substrate; A metal electrode disposed on the upper surface of the inorganic nanobelt array; An organic modification layer, the organic modification layer is disposed on the inorganic nanobelt array and / or in the gaps between the inorganic nanobelt arrays, the organic modification layer connects the inorganic nanobelt array, and the near-infrared II region spectral absorption rate of the organic modification layer is not lower than that of methylene blue, porphyrin compounds or indocyanine green; If an organic modification layer is provided in the gaps between the inorganic nanobelt arrays, the organic modification layer connects the nanobelts on both sides and adjacent to it; The width of the nanobelts of the inorganic nanobelt array is 2 - 200 nm, the thickness is 1 - 20 nm, and the spacing between the nanobelts is 2 - 200 nm.

2. The flexible near-infrared II region photodetector based on two-dimensional material nanoribbons according to claim 1, wherein The material of the organic modification layer is methylene blue, porphyrin compounds or indocyanine green.

3. The flexible near-infrared II region photodetector based on two-dimensional material nanoribbons according to claim 1, wherein The material of the inorganic nanobelt array is graphene, black phosphorus, palladium selenide, hafnium sulfide, platinum sulfide, tin telluride or molybdenum diselenide.

4. The flexible near-infrared II region photodetector based on two-dimensional material nanoribbons according to claim 1, characterized in that The metal electrode includes a positive electrode and a negative electrode, and the organic modification layer is located between the positive electrode and the negative electrode.

5. The preparation method of a near-infrared II region flexible optoelectronic detector based on two-dimensional material nanoribbons according to any one of claims 1 to 4, characterized in that, Including the following steps: S1. Prepare an inorganic nanobelt array on the flexible substrate; S2. Prepare a metal electrode on the inorganic nanobelt array; S3. Prepare an organic modification layer on the upper surface of the flexible substrate and / or on the upper surface of the inorganic nanobelt array.

6. The preparation method of a flexible near-infrared II region photodetector based on two-dimensional material nanoribbons as claimed in claim 5, wherein, The specific process of S1 is: prepare an inorganic nanolayer on the flexible substrate, and etch the inorganic nanolayer to obtain an inorganic nanobelt array.

7. The preparation method of a flexible near-infrared II region photodetector based on two-dimensional material nanoribbons as described in claim 5, characterized in that, The specific process of S3 is: use a spin coating or evaporation method to prepare an organic modification layer on the upper surface of the flexible substrate and / or on the upper surface of the inorganic nanobelt array.

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