Flexible photoelectric detector and preparation method thereof, communication device and wearable equipment
By using the MXene/TiO2 quantum dot composite film layer and the flexible substrate in the flexible photodetector, the shortcomings of traditional flexible photodetectors in terms of photoelectric conversion efficiency and response speed are solved, and the photoelectric performance with high sensitivity and fast response is achieved .
Patent Information
- Application Number
- CN202411371956.2
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-09-29
- Publication Date
- 2025-02-14
AI Technical Summary
Traditional flexible photodetectors have shortcomings in photoelectric conversion efficiency, response speed, etc., and are difficult to meet the growing performance needs.
Using MXene/TiO2 quantum dot composite film layer and flexible substrate, MXene has high conductivity, high light transmittance and wide spectrum response characteristics. TiO2 converts light energy into electrical signals through its excellent photoelectric conversion ability, and interface synergistic effect The photoelectric performance of the detector is further optimized.
It realizes the generation of high-sensitivity photocurrent response under light conditions, optimizes the device's responsiveness and response time, and improves the photoelectric conversion efficiency and response speed.
Smart Images
Figure CN119451247A_ABST
Abstract
Description
Technical Field
[0001] The present application relates to the field of optoelectronic technology, and in particular to a flexible photoelectric detector and a preparation method thereof, a communication device and a wearable device. Background Art
[0002] With the rapid development of optoelectronic technology, traditional photodetectors usually use silicon-based materials, which have great limitations in flexible applications. Flexible photodetectors are increasingly used in wearable devices, smart sensors and other fields. However, traditional flexible photodetectors have shortcomings in terms of photoelectric conversion efficiency and response speed, making it difficult to meet the growing performance requirements. Summary of the invention
[0003] The present application provides a flexible photodetector and a preparation method thereof, a communication device and a wearable device to solve the problems that silicon-based materials in related technologies have great limitations in flexible applications, and traditional flexible photodetectors have deficiencies in photoelectric conversion efficiency, response speed, etc.
[0004] In a first aspect, the present application provides a flexible photodetector, comprising:
[0005] Flexible substrate;
[0006] MXene / TiO 2 Quantum dot composite thin film layer; and
[0007] A transparent electrode layer;
[0008] Wherein, the MXene / TiO 2 MXene and TiO in quantum dot composite film layer 2 The mass ratio of quantum dots is 1:(1~2).
[0009] This application uses MXene / TiO 2 The quantum dot composite film layer is composited with a flexible substrate, in which MXene has high conductivity, high light transmittance and wide spectral response characteristics. Its high conductivity ensures the rapid transmission of photogenerated carriers, while TiO 2 MXene and TiO2 can convert light energy into electrical signals through their excellent photoelectric conversion ability. 2 The interfacial synergistic effect between MXene and TiO further optimizes the photoelectric performance of the detector, enabling the detector to produce a highly sensitive photocurrent response under light conditions. 2 The mass ratio of quantum dots is 1:(1-2) which can optimize the device's responsiveness and response time.
[0010] MXene is a new type of two-dimensional material with excellent electronic, thermal conductivity and mechanical properties. It is prepared by selectively etching ternary layered carbides and has graphene-like two-dimensional structural characteristics. The general chemical formula of MXene materials is Mn+1XnTx, where M represents early transition metal elements, X represents carbon or nitrogen, and Tx represents various functional groups on the surface of the material. Common MXene materials include Ti3C2Tx, Ti2CTx, V2CTx, Nb2CTx, Mo2TiC2Tx, Cr2TiC2Tx, Ta4C3Tx, etc.
[0011] TiO2 quantum dots usually have different crystal structures such as anatase, rutile or brookite, which have important influences on their optical and electronic properties. TiO2 is a wide bandgap semiconductor with a bandgap energy of about 3.2eV, which makes it have strong absorption ability in the ultraviolet region.
[0012] In some embodiments, the material of the flexible substrate includes at least one of polyimide and polydimethylsiloxane. Polyimide has excellent heat resistance, and its glass transition temperature is usually around 300°C, and it can maintain stable physical and chemical properties in a high temperature environment. PDMS has high optical transparency, and the absorption and emission losses from ultraviolet to visible light bands are very small. It has excellent elasticity and flexibility, and improves the flexibility of the photodetector; and / or,
[0013] The material of the transparent electrode layer includes at least one of indium tin oxide and tin fluoride. Indium tin oxide has a visible light transmittance of more than 90% and a low resistivity, while tin fluoride has high light transmittance and good conductivity. It is used as an anti-reflective coating and a transparent conductive layer, and is suitable for applications requiring high transparency.
[0014] In some embodiments, the MXene / TiO 2 The thickness of the quantum dot composite film layer is 10nm~100μm, MXene / TiO 2 The thickness of the quantum dot composite film layer is within this range, which can control the degree of light absorption and regulate the device performance; and / or,
[0015] The thickness of the flexible substrate is 10 μm to 500 μm. When the thickness of the flexible substrate is within this range, a flexible substrate with excellent performance can be prepared, so that it has good mechanical properties and flexibility; and / or,
[0016] The thickness of the transparent electrode layer is 10 nm to 500 nm. When the thickness of the transparent electrode layer is within this range, good electrical contact can be achieved.
[0017] In a second aspect, the present application provides a method for preparing a flexible photodetector, comprising the following steps:
[0018] Preparation of MXene / TiO on flexible substrates 2 Quantum dot composite thin film layer;
[0019] In MXene / TiO 2 A transparent electrode layer is prepared on the quantum dot composite film layer to obtain a flexible photodetector.
[0020] Through MXene / TiO 2 The quantum dot composite film layer is composited with a flexible substrate, in which MXene has high conductivity, high light transmittance and wide spectral response characteristics. Its high conductivity ensures the rapid transmission of photogenerated carriers, while TiO 2 MXene and TiO2 can convert light energy into electrical signals through their excellent photoelectric conversion ability. 2 The interfacial synergistic effect between them further optimizes the photoelectric performance of the detector, enabling the detector to produce a highly sensitive photocurrent response under light conditions.
[0021] In some embodiments, the MXene / TiO 2 The quantum dot composite film layer includes:
[0022] Mixing MXene powder with an organic solvent to obtain a MXene solution;
[0023] Mix MXene solution with TiO 2 Quantum dot mixing to obtain MXene / TiO 2 Quantum dot mixture;
[0024] MXene / TiO 2 The quantum dot mixture is coated on a flexible substrate and dried to obtain MXene / TiO 2 Quantum dot composite thin film layer.
[0025] Organic solvents include, but are not limited to, acetone, propylene oxide, ethyl acetate, acetonitrile, pyridine, phenol, etc. MXene / TiO can be coated by spin coating, spray coating, or blade coating. 2 The quantum dot mixture is coated on a flexible substrate. The MXene solution is mixed with TiO2 quantum dots to obtain MXene / TiO 2 Quantum dot mixture can make MXene and TiO 2 The quantum dots are mixed more evenly in the solution, improving the uniformity of the photodetector.
[0026] TiO is generated by high temperature gas phase reaction 2 Quantum dots can better control the size and shape of the product. Sol-gel method: Sol-gel method is used to prepare uniform and fine TiO 2Quantum dots, commonly used in the preparation of thin films and coatings
[0027] In some embodiments, the MXene solution is mixed with TiO 2 Quantum dot mixing to obtain MXene / TiO 2 In the quantum dot mixture:
[0028] MXene and TiO 2 The mass ratio of the quantum dots is 1:(1-2). The mass ratio of MXene to TiO2 quantum dots is 1:(1-2) to optimize device performance. 2 The quantum dot mixture is coated on a flexible substrate and dried to obtain MXene / TiO 2 In the quantum dot composite film layer:
[0029] The drying temperature is 50-120°C, at which the moisture can be removed well and the material structure can be kept intact; and / or,
[0030] The drying time is 0.5 to 2 hours, within which the material structure will not be destroyed.
[0031] In some embodiments, the MXene / TiO 2 A transparent electrode layer is prepared on the quantum dot composite film layer to obtain a flexible photodetector, and the method for preparing the transparent electrode layer includes any one of vapor deposition, sputtering or printing. In vapor deposition, the plating atoms, molecules or ions are rarely collided during the migration process, so a uniform and dense film layer can be formed on the substrate. The film has a strong bonding force with the substrate, which is conducive to improving the durability and reliability of the product, and making the film have better durability and anti-peeling ability. Sputtering technology bombards the target material with high-energy ions, so that the target atoms are sputtered and evenly deposited on the substrate surface, thereby obtaining better film uniformity. It is suitable for thin film deposition on large-area substrates. The sputtering process can be carried out at a lower temperature, and the film composition and thickness can be precisely controlled.
[0032] In a third aspect, the present application proposes a communication device, comprising the flexible photodetector of the first aspect, or a flexible photodetector manufactured by the method for manufacturing the photodetector of the second aspect.
[0033] In a fourth aspect, the present application proposes a wearable device, comprising the flexible photodetector of the first aspect, or a flexible photodetector made by the preparation method of the photodetector of the second aspect. BRIEF DESCRIPTION OF THE DRAWINGS
[0034] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.
[0035] Figure 1 This is a schematic diagram of the structure of a flexible photodetector according to an embodiment of the present application.
[0036] Description of Figure Numbers:
[0037] 100 Flexible photodetector; 1 Flexible substrate; 2 MXene / TiO 2 Quantum dot composite thin film layer; 3 transparent electrode layer. DETAILED DESCRIPTION
[0038] In order to make the purpose, technical solution and advantages of the present application clearer, the technical solution of the present application will be clearly and completely described below in combination with the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present application.
[0039] With the rapid development of optoelectronic technology, traditional photodetectors usually use silicon-based materials, which have great limitations in flexible applications. Flexible photodetectors are increasingly used in wearable devices, smart sensors and other fields. However, traditional flexible photodetectors have shortcomings in terms of photoelectric conversion efficiency and response speed, making it difficult to meet the growing performance requirements.
[0040] In view of this, the present application provides a flexible photodetector and a preparation method thereof, a communication device and a wearable device to solve the problems that silicon-based materials in related technologies have great limitations in flexible applications, and traditional flexible photodetectors have deficiencies in photoelectric conversion efficiency, response speed, etc.
[0041] like Figure 1 As shown, in a first aspect, the present application provides a flexible photodetector 100, comprising:
[0042] Flexible substrate 1;
[0043] MXene / TiO 2 Quantum dot composite thin film layer 2; and
[0044] Transparent electrode layer 3;
[0045] Wherein, the MXene / TiO2 MXene and TiO in quantum dot composite film layer 2 2 The mass ratio of quantum dots is 1:(1~2).
[0046] This application uses MXene / TiO 2 The quantum dot composite film layer 2 is composited with the flexible substrate 1, wherein MXene has high conductivity, high light transmittance and wide spectral response characteristics. Its high conductivity ensures the rapid transmission of photogenerated carriers, while TiO 2 MXene and TiO2 can convert light energy into electrical signals through their excellent photoelectric conversion ability. 2 The interface synergistic effect between the MXene and TiO2 quantum dots further optimizes the photoelectric performance of the detector, so that the detector can produce a highly sensitive photocurrent response under light conditions. The mass ratio of MXene to TiO2 quantum dots is 1: (1-2) which can optimize the responsiveness and response time of the device. 2 The mass ratio of quantum dots includes, but is not limited to, 1:1, 1:1.1, 1:1.2, 1:1.3, 1:1.4, 1:1.5, 1:1.6, 1:1.7, 1:1.8, 1:1.9 or 1:2.
[0047] MXene is a new type of two-dimensional material with excellent electronic, thermal conductivity and mechanical properties. It is prepared by selectively etching ternary layered carbides and has graphene-like two-dimensional structural characteristics. The general chemical formula of MXene materials is Mn+1XnTx, where M represents early transition metal elements, X represents carbon or nitrogen, and Tx represents various functional groups on the surface of the material. Common MXene materials include Ti3C2Tx, Ti2CTx, V2CTx, Nb2CTx, Mo2TiC2Tx, Cr2TiC2Tx, Ta4C3Tx, etc.
[0048] TiO2 quantum dots usually have different crystal structures such as anatase, rutile or brookite, which have important influences on their optical and electronic properties. TiO2 is a wide bandgap semiconductor with a bandgap energy of about 3.2eV, which makes it have strong absorption ability in the ultraviolet region.
[0049] In combination with the first aspect, in some embodiments provided in the present application, the material of the flexible substrate 1 includes at least one of polyimide and polydimethylsiloxane, polyimide has excellent heat resistance, and its glass transition temperature is usually around 300°C, and it can maintain stable physical and chemical properties in a high temperature environment, PDMS has high optical transparency, and the absorption and emission losses from ultraviolet to visible light bands are very small, and it has excellent elasticity and flexibility, which improves the flexibility of the photodetector; and / or,
[0050] The material of the transparent electrode layer 3 includes at least one of indium tin oxide and tin fluoride. Indium tin oxide has a visible light transmittance of more than 90% and a low resistivity, while tin fluoride has high light transmittance and good conductivity. It is used as an anti-reflective coating and a transparent conductive layer and is suitable for applications requiring high transparency.
[0051] In combination with the first aspect, in some embodiments provided in the present application, the MXene / TiO 2 The thickness of the quantum dot composite film layer 2 is 10nm to 100μm, and the MXene / TiO 2 The thickness of quantum dot composite film layer 2 affects the degree of light absorption, MXene / TiO 2 The thickness of the quantum dot composite film layer 2 is within this range, which can well control the degree of light absorption and regulate the device performance. 2 The thickness of the quantum dot composite thin film layer 2 includes, but is not limited to, 10 μm, 20 μm, 30 μm, 40 μm, 50 μm, 60 μm, 70 μm, 80 μm, 90 μm or 100 μm.
[0052] In combination with the first aspect, in some embodiments provided in the present application, the thickness of the flexible substrate 1 is 10 μm to 500 μm, and the thickness of the flexible substrate 1 affects the mechanical properties and flexibility. When the thickness of the flexible substrate 1 is within this range, the flexible substrate can be well prepared to have good mechanical properties and flexibility. The thickness of the flexible substrate 1 includes but is not limited to 10 μm, 50 μm, 100 μm, 150 μm, 200 μm, 250 μm, 300 μm, 350 μm, 400 μm, 450 μm or 500 μm.
[0053] In combination with the first aspect, in some embodiments provided in the present application, the thickness of the transparent electrode layer 3 is 10nm to 500nm. The thickness of the electrode layer 3 affects the tightness of the contact with the substrate. When the thickness of the transparent electrode layer 3 is within this range, good electrical contact can be achieved. The thickness of the transparent electrode layer 3 includes but is not limited to 10nm, 50nm, 100nm, 150nm, 200nm, 250nm, 300nm, 350nm, 400nm, 450nm or 500nm.
[0054] In a second aspect, the present application provides a method for preparing a flexible photodetector 100, comprising the following steps:
[0055] Preparation of MXene / TiO on flexible substrate 1 2 Quantum dot composite thin film layer 2;
[0056] In MXene / TiO 2A transparent electrode layer 3 is prepared on the quantum dot composite thin film layer 2 to obtain a flexible photodetector 100.
[0057] Through MXene / TiO 2 The quantum dot composite film layer 2 is composited with the flexible substrate 1, wherein MXene has high conductivity, high light transmittance and wide spectral response characteristics. Its high conductivity ensures the rapid transmission of photogenerated carriers, while TiO 2 MXene and TiO2 can convert light energy into electrical signals through their excellent photoelectric conversion ability. 2 The interfacial synergistic effect between them further optimizes the photoelectric performance of the detector, enabling the detector to produce a highly sensitive photocurrent response under light conditions.
[0058] In combination with the second aspect, in some embodiments provided in the present application, the MXene / TiO 2 The quantum dot composite thin film layer 2 comprises:
[0059] Mixing MXene powder with an organic solvent to obtain a MXene solution;
[0060] Mix MXene solution with TiO 2 Quantum dot mixing to obtain MXene / TiO 2 Quantum dot mixture;
[0061] MXene / TiO 2 The quantum dot mixture is coated on the flexible substrate 1 and dried to obtain MXene / TiO 2 Quantum dot composite thin film layer 2.
[0062] Organic solvents include, but are not limited to, acetone, propylene oxide, ethyl acetate, acetonitrile, pyridine, phenol, etc. MXene / TiO can be coated by spin coating, spray coating, or blade coating. 2 The quantum dot mixture is coated on the flexible substrate 1. The MXene solution is mixed with TiO 2 Quantum dot mixing to obtain MXene / TiO 2 Quantum dot mixture can make MXene and TiO 2 The quantum dots are mixed more evenly in the solution, improving the uniformity of the photodetector.
[0063] TiO is generated by high temperature gas phase reaction 2 Quantum dots can better control the size and shape of the product. Sol-gel method: Sol-gel method is used to prepare uniform and fine TiO 2 Quantum dots are often used in the preparation of thin films and coatings.
[0064] In combination with the second aspect, in some embodiments provided in the present application, the MXene solution is mixed with TiO 2 Quantum dot mixing to obtain MXene / TiO 2 In the quantum dot mixture:
[0065] MXene and TiO 2 The mass ratio of quantum dots is 1:(1~2). MXene and TiO 2 The mass ratio of quantum dots is 1:(1-2) which can optimize the device's responsiveness and response time. 2 The mass ratio of quantum dots includes, but is not limited to, 1:1, 1:1.1, 1:1.2, 1:1.3, 1:1.4, 1:1.5, 1:1.6, 1:1.7, 1:1.8, 1:1.9 or 1:2.0.
[0066] In combination with the second aspect, in some embodiments provided in the present application, the MXene / TiO 2 The quantum dot mixture is coated on the flexible substrate 1 and dried to obtain MXene / TiO 2 In the quantum dot composite film layer 2: the drying temperature is 50-120°C. At this drying temperature, moisture can be removed well to keep the material structure intact. The drying temperature includes but is not limited to 50°C, 60°C, 70°C, 80°C, 90, 100°C, 110°C or 120°C.
[0067] In combination with the second aspect, in some embodiments provided in the present application, the MXene / TiO 2 The quantum dot mixture is coated on the flexible substrate 1 and dried to obtain MXene / TiO 2 In the quantum dot composite film layer 2: the drying time is 0.5 to 2 hours, and the material structure may not be damaged under this drying time. The drying time includes but is not limited to 0.5 hours, 0.7 hours, 1.0 hours, 1.2 hours, 1.5 hours, 1.8 hours or 2.0 hours.
[0068] In combination with the second aspect, in some embodiments provided in the present application, the MXene / TiO 2A transparent electrode layer 3 is prepared on the quantum dot composite film layer 2 to obtain a flexible photodetector 100, and the method for preparing the transparent electrode layer 3 includes any one of vapor deposition, sputtering or printing. In vapor deposition, the plating atoms, molecules or ions are rarely collided during the migration process, so a uniform and dense film layer can be formed on the substrate, and there is a strong bonding force between the film and the substrate, which is conducive to improving the durability and reliability of the product, so that the film has better durability and anti-peeling ability. Sputtering technology bombards the target material with high-energy ions, so that the target atoms are sputtered and evenly deposited on the surface of the substrate, thereby obtaining better film uniformity, which is suitable for thin film deposition on large-area substrates. The sputtering process can be carried out at a lower temperature, and the film composition and thickness can be accurately controlled.
[0069] In a third aspect, the present application proposes a communication device, comprising the flexible photodetector 100 of the first aspect, or the flexible photodetector 100 made by the photodetector preparation method of the second aspect. The communication device has all the beneficial effects of the flexible photodetector 100, which are not described in detail in this application. It should be noted that the communication device includes but is not limited to an optical receiver.
[0070] In a fourth aspect, the present application proposes a wearable device, comprising the flexible photodetector 100 of the first aspect, or the flexible photodetector 100 prepared by the preparation method of the photodetector of the second aspect. The wearable device has all the beneficial effects of the flexible photodetector 100, which will not be described in detail in this application. It should be noted that the wearable device includes but is not limited to a smart bracelet and AR glasses.
[0071] The technical solution provided in this application is described in detail below in conjunction with embodiments.
[0072] Example 1
[0073] Embodiment 1 of the present application provides a method for preparing a flexible photodetector, comprising the following steps:
[0074] Dispersing MXene powder in an organic solvent, ethanol, to obtain a MXene solution;
[0075] Mix MXene solution with TiO 2 Quantum dot mixing to obtain MXene / TiO 2 Quantum dot mixture, in which MXene and TiO 2 The mass ratio of quantum dots is 1:1;
[0076] MXene / TiO 2 The quantum dot mixture was coated on a 300 μm thick flexible substrate polydimethylsiloxane and dried at 65 °C for 0.5 h to obtain a 10 μm thick MXene / TiO2 Quantum dot composite thin film layer;
[0077] In MXene / TiO 2 A 300nm thick transparent electrode layer of tin fluoride is prepared by vapor deposition on the quantum dot composite film layer to obtain a flexible photodetector.
[0078] Example 2
[0079] Embodiment 2 of the present application provides a method for preparing a flexible photoelectric detector, comprising the following steps:
[0080] Dispersing MXene powder in an organic solvent, ethanol, to obtain a MXene solution;
[0081] Mix MXene solution with TiO 2 Quantum dot mixing to obtain MXene / TiO 2 Quantum dot mixture, in which MXene and TiO 2 The mass ratio of quantum dots is 1:2;
[0082] MXene / TiO 2 The quantum dot mixture was coated on a 500 μm thick flexible substrate polydimethylsiloxane and dried at 50 °C for 2 h to obtain a 100 μm thick MXene / TiO 2 Quantum dot composite thin film layer;
[0083] In MXene / TiO 2 A 500nm thick transparent electrode layer of tin fluoride is prepared by vapor deposition on the quantum dot composite film layer to obtain a flexible photodetector.
[0084] Example 3
[0085] Embodiment 3 of the present application provides a method for preparing a flexible photoelectric detector, comprising the following steps:
[0086] Dispersing MXene powder in an organic solvent, ethanol, to obtain a MXene solution;
[0087] Mix MXene solution with TiO 2 Quantum dot mixing to obtain MXene / TiO 2 Quantum dot mixture, in which MXene and TiO 2 The mass ratio of quantum dots is 1:1.5;
[0088] MXene / TiO 2 The quantum dot mixture was coated on a 100 μm thick flexible substrate polyimide and dried at 120 °C for 0.5 h to obtain a 20 μm thick MXene / TiO 2 Quantum dot composite thin film layer;
[0089] In MXene / TiO 2 A 100nm thick transparent electrode layer of indium tin oxide is prepared by vapor deposition on the quantum dot composite film layer to obtain a flexible photodetector.
[0090] Comparative Example 1
[0091] Comparative Example 1 of the present application provides a method for preparing a flexible photodetector, comprising the following steps:
[0092] Dispersing MXene powder in an organic solvent, ethanol, to obtain a MXene solution;
[0093] The MXen solution was coated on a 300 μm thick flexible substrate polyimide and dried at 65 °C for 0.5 h to obtain a MXene film layer;
[0094] A 300nm thick transparent electrode layer of indium tin oxide was prepared by vapor deposition on the MXene thin film layer to obtain a flexible photodetector.
[0095] Comparative Example 1 does not contain TiO 2 Quantum dots do not form a heterojunction structure. When illuminated, the photocurrent is mainly provided by Mxene, so the response switching ratio is relatively small and the response speed is slow.
[0096] Comparative Example 2
[0097] Comparative Example 2 of the present application provides a method for preparing a flexible photodetector, comprising the following steps:
[0098] TiO 2 The quantum dot solution was coated on a 300 μm thick flexible substrate polyimide and dried at 65 °C for 0.5 h to obtain a 10 μm thick TiO 2 Quantum dot thin film layer;
[0099] In TiO 2 A 300nm thick transparent electrode layer of indium tin oxide is prepared by vapor deposition on the quantum dot film layer to obtain a flexible photodetector.
[0100] Since Comparative Example 2 does not contain MXene and does not form a heterojunction structure, when illuminated, the photocurrent is mainly provided by TiO2, so the response speed is relatively slow.
[0101] Comparative Example 3
[0102] Comparative Example 3 provides a method for preparing a flexible photodetector, comprising the following steps:
[0103] The tin dioxide quantum dot solution was coated on a 300 μm thick flexible substrate polyimide and dried at 65°C for 0.5 h to obtain a 10 μm thick tin dioxide film layer;
[0104] A 300nm thick transparent electrode layer of indium tin oxide is prepared by vapor deposition on the tin dioxide film layer to obtain a flexible photodetector.
[0105] Comparative Example 3 does not contain MXene and TiO 2 Quantum dots, therefore no device response performance.
[0106] Performance Testing
[0107] The flexible photodetectors of Examples 1 to 3 and Comparative Examples 1 to 3 were tested to test their photogenerated carrier transmission performance and photocurrent response performance. The specific test results are shown in Table 1.
[0108] After the flexible photodetectors of Examples 1 to 3 and Comparative Examples 1 to 3 were prepared into corresponding devices, they were tested under illumination conditions by using the current-voltage characteristic curve method to determine their response switching ratio and response time based on the current variation curve over time.
[0109] Table 1 Performance of flexible photodetectors of Examples 1 to 3 and Comparative Examples 1 to 3
[0110]
[0111]
[0112] As shown in Table 1, the transport performance and photocurrent response performance of the photogenerated carriers in Examples 1 to 3 are better than those in Comparative Examples 1 and 2, and are comparable to those in Comparative Example 3, indicating that the MXene / TiO 2 Quantum dot flexible photodetector preparation method, using the high conductivity of MXene and TiO 2 The high photoelectric conversion efficiency of quantum dots enables the high-performance preparation of detectors. The preparation method is simple and reproducible, and can be applied to large-scale production. The prepared detector has high photoelectric conversion efficiency, fast response and good flexibility, and can be widely used in wearable devices, smart sensors and other fields.
[0113] Comparative Example 1 does not contain TiO 2 Quantum dots, so the device switching ratio is relatively small.
[0114] Since Comparative Example 2 does not contain MXene, the response speed is relatively slow.
[0115] Comparative Example 3 does not contain MXene and TiO 2 quantum dots, and therefore no device response.
[0116] This indicates that the formation of a heterojunction structure in the device is beneficial to the transport of carriers and improves the response speed.
[0117] In summary, through MXene / TiO 2 The quantum dot composite film layer is composited with a flexible substrate, in which MXene has high conductivity, high light transmittance and wide spectral response characteristics. Its high conductivity ensures the rapid transmission of photogenerated carriers, while TiO 2 MXene and TiO2 can convert light energy into electrical signals through their excellent photoelectric conversion ability. 2 The interfacial synergistic effect between MXene and TiO further optimizes the photoelectric performance of the detector, enabling the detector to produce a highly sensitive photocurrent response under light conditions. 2 The mass ratio of quantum dots is 1:(1-2) which can optimize the device's responsiveness and response time.
[0118] In the description of this specification, the description with reference to the terms "one embodiment / method", "some embodiments / methods", "example", "specific example" or "some examples" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment / method or example are included in at least one embodiment / method or example of the present application. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment / method or example. Moreover, the specific features, structures, materials or characteristics described may be combined in a suitable manner in any one or more embodiments / methods or examples. In addition, those skilled in the art may combine and combine the different embodiments / methods or examples described in this specification and the features of the different embodiments / methods or examples, unless they are contradictory.
[0119] It should be noted that, in the present application, relational terms such as "first" and "second" are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply that there is any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that the process, method, article or equipment including a series of elements includes not only those elements, but also includes other elements not explicitly listed, or also includes elements inherent to such process, method, article or equipment. In the absence of more restrictions, the elements defined by the sentence "comprise one..." do not exclude the existence of other identical elements in the process, method, article or equipment including the elements. In the present application, the meaning of "multiple" is at least two, such as two, three, etc., unless otherwise clearly and specifically stipulated.
[0120] The above description is only a specific implementation of the present application, so that those skilled in the art can understand or implement the present application. Various modifications to these embodiments will be apparent to those skilled in the art, and the general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of the present application. Therefore, the present application will not be limited to the embodiments shown herein, but will conform to the widest range consistent with the principles and novel features applied for herein.
Claims
1. A flexible photodetector, characterized in that: Including the following from bottom to top: Flexible substrate; MXene / TiO2 quantum dot composite thin film layer; and A transparent electrode layer; Wherein, the mass ratio of MXene to TiO2 quantum dots in the MXene / TiO2 quantum dot composite thin film layer is 1:(1-2).
2. The flexible photodetector according to claim 1, characterized in that: The material of the flexible substrate includes at least one of polyimide and polydimethylsiloxane; and / or, The material of the transparent electrode layer includes at least one of indium tin oxide and tin fluoride.
3. The flexible photodetector according to claim 1, characterized in that: The thickness of the MXene / TiO2 quantum dot composite film layer is 10nm to 100μm; and / or, The thickness of the flexible substrate is 10 μm to 500 μm; and / or, The thickness of the transparent electrode layer is 10nm to 500nm.
4. A method for preparing a flexible photodetector according to any one of claims 1 to 3, characterized in that: The following steps are involved: Preparation of MXene / TiO2 quantum dot composite thin film layer on flexible substrate; A transparent electrode layer is prepared on the MXene / TiO2 quantum dot composite thin film layer to obtain a flexible photodetector.
5. The method for preparing a flexible photodetector according to claim 4, characterized in that: The method of preparing a MXene / TiO2 quantum dot composite thin film layer on a flexible substrate comprises: Mixing MXene powder with an organic solvent to obtain a MXene solution; Mixing the MXene solution with TiO2 quantum dots to obtain a MXene / TiO2 quantum dot mixed solution; The MXene / TiO2 quantum dot mixed solution is coated on a flexible substrate and dried to obtain a MXene / TiO2 quantum dot composite thin film layer.
6. The method for preparing a flexible photodetector according to claim 5, characterized in that: The MXene solution is mixed with TiO2 quantum dots to obtain a MXene / TiO2 quantum dot mixed solution: The mass ratio of MXene to TiO2 quantum dots is 1:(1~2).
7. The method for preparing the flexible photodetector according to claim 5, characterized in that: The MXene / TiO2 quantum dot mixed solution is coated on a flexible substrate and dried to obtain a MXene / TiO2 quantum dot composite thin film layer: The drying temperature is 50 to 120°C; and / or, The drying time is 0.5 to 2 hours.
8. The method for preparing a flexible photodetector according to claim 4, characterized in that: In the flexible photodetector obtained by preparing a transparent electrode layer on the MXene / TiO2 quantum dot composite thin film layer, the method for preparing the transparent electrode layer includes any one of vapor deposition, sputtering or printing.
9. A communication device, characterized in that: The invention comprises a flexible photodetector as described in any one of claims 1 to 3, or a flexible photodetector prepared by the method for preparing a flexible photodetector as described in any one of claims 4 to 8.
10. A wearable device, characterized in that: The invention comprises a flexible photodetector as described in any one of claims 1 to 3, or a flexible photodetector prepared by the method for preparing a flexible photodetector as described in any one of claims 4 to 8.