Infrared detection device and preparation method thereof

Abstract

The invention provides an infrared detection device and a preparation method of the infrared detection device, the infrared detection device comprises a quantum dot function layer and a top electrode layer, the top electrode layer is arranged on the surface of the quantum dot function layer, and the top electrode layer is used for protecting the quantum dot function layer from being eroded by water and oxygen. According to the technical scheme provided by the embodiment of the invention, the top electrode layer is arranged on the surface of the quantum dot functional layer, and the top electrode layer is used for protecting the quantum dot functional layer from being eroded by water and oxygen. The water and oxygen blocking capability of the device is ensured, the service life is prolonged, and the device adapts to a worse working environment.

Description

Technical Field

[0001] The present application relates to the field of infrared detection technology, and in particular to an infrared detection device and a method for preparing the infrared detection device. Background Art

[0002] Infrared light is a form of electromagnetic radiation that is ubiquitous in natural and artificial environments. Infrared imaging technology has greater application potential in emerging fields such as intelligent sensing, machine vision, and autonomous driving. However, infrared light cannot be directly perceived by the naked eye. Therefore, infrared photodetectors were invented to detect infrared light, and photoactive materials play a vital role in this process, among which semiconductor materials are usually used. Commercial infrared photodetectors are usually made of traditional narrow-bandgap bulk inorganic semiconductors (such as InSb, Ge, HgCdTe, InGaAs). However, bulk semiconductor materials are quite limited. First, they are usually grown under extreme temperature and vacuum conditions, which is very costly. Second, the epitaxial growth method commonly used is epitaxial growth on a lattice-matched crystal substrate, which makes this type of infrared photodetector expensive, inflexible, and limited. Therefore, there is an urgent need for alternative materials for infrared detectors with small size, low dark current, and low energy consumption.

[0003] Compared with traditional bulk semiconductors, infrared quantum dots have the advantages of easy processing, good flexibility and photostability, and high absorption coefficient. Colloidal quantum dot infrared detectors have the advantages of adjustable corresponding bands, excellent detection performance, low price, and process compatibility, showing great potential to replace silicon-based pixel arrays and achieve full coverage imaging in the short-wave infrared band. Due to the short development time of PbS CQDs, the industry's research on thin film packaging and stability of PbS CQDs detectors is basically in a blank stage. Therefore, conducting thin film packaging research on colloidal quantum dot detectors has important use value and scientific significance for achieving high detector life, excellent stability, and industrial application.

[0004] Application Contents

[0005] In view of the above problems, the present application provides an infrared detection device and a method for preparing the infrared detection device.

[0006] In a first aspect, an infrared detection device is provided, comprising:

[0007] Quantum dot functional layer;

[0008] A top electrode layer is disposed on the surface of the quantum dot functional layer, wherein the top electrode layer is used to protect the quantum dot functional layer from being corroded by water and oxygen.

[0009] Wherein, the top electrode layer is made of light-transmitting and waterproof material.

[0010] Wherein, the top electrode layer is an indium tin oxide film.

[0011] Wherein, the infrared detection device also includes:

[0012] The encapsulation layer is arranged on a side of the top electrode layer away from the quantum dot functional layer, and is used to protect the quantum dot functional layer from being corroded by water and oxygen.

[0013] Wherein, the encapsulation layer comprises:

[0014] A first encapsulation layer is disposed on a side of the top electrode layer away from the quantum dot functional layer;

[0015] A second encapsulation layer is disposed on a side of the first encapsulation layer away from the quantum dot functional layer;

[0016] The third packaging layer is arranged on a side of the second packaging layer away from the quantum dot functional layer.

[0017] Wherein, the first encapsulation layer and the third encapsulation layer are Al2O3 films formed by atomic layer deposition;

[0018] The second encapsulation layer is a transparent organic film.

[0019] Wherein, the quantum dot functional layer includes, in order from the direction away from the top electrode layer to the direction close to the top electrode layer:

[0020] Bottom electrode layer, electron blocking layer, p-type layer, active layer, electron transport layer, strong n-type layer.

[0021] In a second aspect, a method for preparing an infrared detection device is provided, comprising:

[0022] preparing the quantum dot functional layer;

[0023] An indium tin oxide film is sputtered on the surface of the quantum dot functional layer by a magnetron sputtering method, and the indium tin oxide film is patterned by a laser etching / photolithography / nanoimprinting process to form a top electrode layer; wherein the top electrode layer is used to protect the quantum dot functional layer from water and oxygen corrosion.

[0024] Wherein, the method further comprises:

[0025] Performing atomic layer deposition on a side of the top electrode layer away from the quantum dot functional layer, and patterning the top electrode layer using a laser etching / photolithography / nanoimprinting process to form a first encapsulation layer;

[0026] An organic thin film layer is formed on a side of the first encapsulation layer away from the quantum dot functional layer by using inkjet printing / spin coating / printing / lamination / evaporation technology, and patterned by using laser etching / photolithography / nanoimprinting process to form a second encapsulation layer;

[0027] Atomic layer deposition is performed on a side of the second encapsulation layer away from the quantum dot functional layer, and patterning is performed using a laser etching / photolithography / nanoimprinting process to form a third encapsulation layer.

[0028] Wherein, the step of preparing the quantum dot functional layer comprises:

[0029] providing a substrate;

[0030] Sputtering an indium tin oxide film on the surface of the substrate by a magnetron sputtering method, and patterning the indium tin oxide film by a laser etching process to form a bottom electrode layer;

[0031] An electron blocking layer, a p-type layer, an active layer, an electron transport layer, and a strong n-type layer are sequentially arranged on the bottom electrode layer;

[0032] Wherein, the top electrode layer is arranged on a side of the strong n-type layer away from the bottom electrode layer.

[0033] The technical solution provided in the embodiment of the present application is to set a top electrode layer on the surface of the quantum dot functional layer, and the top electrode layer is used to protect the quantum dot functional layer from water and oxygen erosion, thereby ensuring the water and oxygen barrier capacity of the device, improving its service life, and adapting to a more severe working environment.

[0034] The above description is only an overview of the technical solution of the present application. In order to more clearly understand the technical means of the present application, it can be implemented in accordance with the contents of the specification. In order to make the above and other purposes, features and advantages of the present application more obvious and easy to understand, the specific implementation methods of the present application are listed below. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Various other advantages and benefits will become apparent to those of ordinary skill in the art by reading the detailed description of the preferred embodiments below. The accompanying drawings are only for the purpose of illustrating the preferred embodiments and are not to be considered as limiting the present application. Also, the same reference symbols are used throughout the accompanying drawings to represent the same components. In the accompanying drawings:

[0036] Figure 1 It is a structural schematic diagram of an embodiment of the infrared detection device of the present application;

[0037] Figure 2 It is a schematic flow chart of an embodiment of a method for preparing an infrared detection device of the present application;

[0038] Figure 3It is a flow chart of another embodiment of the method for preparing the infrared detection device of the present application. DETAILED DESCRIPTION

[0039] Exemplary embodiments of the present disclosure will be described in more detail below with reference to the accompanying drawings. Although exemplary embodiments of the present disclosure are shown in the accompanying drawings, it should be understood that the present disclosure can be implemented in various forms and should not be limited by the embodiments set forth herein. On the contrary, these embodiments are provided in order to enable a more thorough understanding of the present disclosure and to be able to fully convey the scope of the present disclosure to those skilled in the art. In addition, in the following description, descriptions of well-known structures and technologies are omitted to avoid unnecessary confusion of the concepts of the present disclosure.

[0040] Various structural schematic diagrams according to embodiments of the present disclosure are shown in the accompanying drawings. These figures are not drawn to scale, and some details are magnified and some details may be omitted for the purpose of clear expression. The shapes of various regions and layers shown in the figures and the relative sizes and positional relationships therebetween are only exemplary, and may deviate in practice due to manufacturing tolerances or technical limitations, and those skilled in the art may further design regions / layers with different shapes, sizes, and relative positions according to actual needs.

[0041] The ultrasonic imaging device of the present application is described in detail below with reference to the accompanying drawings.

[0042] See first Figure 1 , Figure 1 The schematic diagram of the structure of an embodiment of the infrared detection device of the present application specifically includes: a quantum dot functional layer 11 and a top electrode layer 12. In this embodiment, the top electrode layer 12 is disposed on the surface of the quantum dot functional layer 11, and the top electrode layer 12 is used to protect the quantum dot functional layer 11 from being corroded by water and oxygen.

[0043] In one embodiment, the top electrode layer 12 is made of a light-transmitting and waterproof material. Preferably, the top electrode layer 12 is an indium tin oxide (ITO) film. The thickness of the indium tin oxide (ITO) film is 20 nm to 1000 nm.

[0044] The quantum dot functional layer in the colloidal quantum dot detection device is easily corroded by water and oxygen in the air, which causes the performance of the detector to drop sharply, the device to be damaged or even fail, greatly reduces its service life, and severely limits its use scenarios. The present invention replaces the top electrode of the detection device with a light-transmitting and waterproof material to protect the quantum dot functional layer 11 from water and oxygen corrosion. In a specific embodiment, the present invention replaces the top electrode of the detection device with a dense and transparent indium tin oxide ITO thin film layer to ensure its water and oxygen barrier ability, improve its service life, and adapt to harsher working environments.

[0045] Furthermore, the infrared detection device further includes an encapsulation layer 13, which is disposed on a side of the top electrode layer 12 away from the quantum dot functional layer 11, and is used to protect the quantum dot functional layer 11 from being corroded by water and oxygen. The encapsulation layer 13 is disposed so that the encapsulation layer 13 and the top electrode layer 12 together form a composite thin film encapsulation layer, thereby increasing the encapsulation effect and further ensuring the ability of the chip to block water and oxygen.

[0046] In one embodiment, the encapsulation layer 13 includes: a first encapsulation layer 131, a second encapsulation layer 132 and a third encapsulation layer 133. The first encapsulation layer 131 is disposed on a side of the top electrode layer 12 away from the quantum dot functional layer 11; the second encapsulation layer 132 is disposed on a side of the first encapsulation layer 131 away from the quantum dot functional layer 11; and the third encapsulation layer 133 is disposed on a side of the second encapsulation layer 132 away from the quantum dot functional layer 11.

[0047] In a specific embodiment, the first encapsulation layer 131 and the third encapsulation layer 133 are Al2O3 films formed by atomic layer deposition, with a thickness of 5nm to 1000nm. Among them, the first encapsulation layer and the third encapsulation layer of Al2O3 have dense films, strong water and oxygen blocking capabilities, precisely controlled thickness, and strong infrared transmittance. The second encapsulation layer 132 is a transparent organic film; specifically, the second encapsulation layer 132 includes any one or any combination of PMMA (polymethyl methacrylate), polyimide, polycarbonate, epoxy resin, polyethylene (PE), and polyacrylate (PA), with a thickness of 100nm to 20000nm.

[0048] The infrared detection device of the present invention realizes a thin film packaging structure of the detector through a four-layer packaging (top electrode layer 12, first packaging layer 131, second packaging layer 132 and third packaging layer 133) structure, thereby protecting the detection device from water and oxygen, improving its service life, adapting to harsher working environments, and ensuring the transmittance of infrared light.

[0049] Furthermore, the quantum dot functional layer 11 in the infrared detection device of the present application includes, in order from the direction away from the top electrode layer 12 to the direction close to the top electrode layer 12: a bottom electrode layer 111, an electron blocking layer 112, a p-type layer 113, an active layer 114, an electron transport layer 115, and a strong n-type layer 116.

[0050] The material of the bottom electrode layer 111 is the same as that of the top electrode layer 12 , both of which are indium tin oxide thin films.

[0051] The material of the strong n-type layer 116 is SnO 2 .

[0052] The material of the electron transport layer 115 is C60 .

[0053] The material of the p-type layer 113 includes one or a mixture of PbS, 1,2-ethanedithiol, tetramethylsilane, and acetonitrile.

[0054] The material of the electron blocking layer 112 is NiOX.

[0055] The electron blocking layer 112 is of p-type, the active layer 114 is of i-type, and the electron transport layer 115 is of n-type.

[0056] The electron blocking layer 112, the p-type layer 113, the active layer 114, the electron transport layer 115, and the strong n-type layer 116 form a pin structure as a whole. The four-layer packaging (top electrode layer 12, first packaging layer 131, second packaging layer 132, and third packaging layer 133) structure realizes the thin film packaging structure of the detector, realizes the water and oxygen protection of the detection device (pin structure), improves its service life, adapts to a more severe working environment, and ensures the transmittance of infrared light.

[0057] See also Figure 2 , Figure 2 This is a flow chart of an embodiment of a method for preparing an infrared detection device of the present application, which specifically includes:

[0058] Step S21: preparing the quantum dot functional layer.

[0059] Specifically, the quantum dot functional layer includes, from bottom to top, a bottom electrode layer, an electron blocking layer, a p-type layer, an active layer, an electron transport layer, and a strong n-type layer.

[0060] In a specific embodiment, a substrate is provided; an indium tin oxide film is sputtered on the surface of the substrate by a magnetron sputtering method, and the indium tin oxide film is patterned by a laser etching process to form a bottom electrode layer; an electron blocking layer, a p-type layer, an active layer, an electron transport layer, and a strong n-type layer are sequentially arranged on the bottom electrode layer.

[0061] The material of the bottom electrode layer is the same as that of the top electrode layer, both of which are indium tin oxide thin films.

[0062] Wherein, the material of the strong n-type layer is SnO2.

[0063] Among them, the material of the electron transport layer is C 60 .

[0064] The material of the p-type layer includes one or a mixture of PbS, 1,2-ethanedithiol, tetramethylsilane, and acetonitrile.

[0065] Wherein, the material of the electron blocking layer is NiOX.

[0066] The electron blocking layer is of p-type, the active layer is of i-type, and the electron transport layer is of n-type.

[0067] Among them, the electron blocking layer, the p-type layer, the active layer, the electron transport layer, and the strong n-type layer form a pin structure as a whole.

[0068] Step S22: sputtering an indium tin oxide film on the surface of the quantum dot functional layer by a magnetron sputtering method, and patterning the indium tin oxide film by laser etching / photolithography / nanoimprinting process to form a top electrode layer; wherein the top electrode layer is used to protect the quantum dot functional layer from water and oxygen corrosion.

[0069] In a specific embodiment, the top electrode layer is arranged on a side of the strong n-type layer away from the bottom electrode layer. Specifically, on the surface of the strong n-type layer on the upper surface of the device away from the bottom electrode layer, a magnetron sputtering method is used to sputter an indium tin oxide ITO film at 1*10-3pa, with an oxygen-argon ratio of 0.1:28, a sputtering power of 100W, a sputtering time of 20min, and an indium tin oxide ITO film thickness of 20nm to 1000nm, which meets the electrical, light-transmitting, and water-oxygen blocking effects. The indium tin oxide ITO film is further patterned using laser etching / photolithography / nanoimprinting technology to ensure that the ITO is completely etched and not short-circuited. At the same time, the performance of the detection chip is not affected, thereby forming a top electrode layer.

[0070] The quantum dot functional layer in the colloidal quantum dot detection device is easily corroded by water and oxygen in the air, which causes the performance of the detector to drop sharply, the device to be damaged or even fail, greatly reduces its service life, and severely limits its use scenarios. The present invention replaces the top electrode of the detection device with a light-transmitting and waterproof material to protect the quantum dot functional layer from water and oxygen corrosion. In a specific embodiment, the present invention replaces the top electrode of the detection device with a dense and transparent indium tin oxide ITO thin film layer to ensure its water and oxygen barrier ability, improve its service life, and adapt to harsher working environments.

[0071] Please combine Figure 3 , Figure 3 This is a flow chart of a second embodiment of the method for preparing an infrared detection device of the present application, which is similar to the above Figure 2 Compared with the embodiment shown in the figure, this embodiment further includes after step S22:

[0072] Step S23: performing atomic layer deposition on a side of the top electrode layer away from the quantum dot functional layer, and patterning the layer using a laser etching / photolithography / nanoimprinting process to form a first encapsulation layer.

[0073] Specifically, 5nm to 1000nm of Al2O3 is deposited by atomic layer deposition (ALD) on the surface of the top electrode layer away from the quantum dot functional layer, and patterned by laser etching / photolithography / nanoimprinting process to form a first encapsulation layer. It should be noted that the temperature during deposition is 50℃ to 200℃ to avoid damage to the device.

[0074] Step S24: using inkjet printing / spin coating / printing / lamination / evaporation technology to form an organic thin film layer on the side of the first encapsulation layer away from the quantum dot functional layer, and patterning it using laser etching / photolithography / nanoimprinting technology to form a second encapsulation layer.

[0075] An organic thin film layer with high transmittance to infrared light is made on the surface of the first encapsulation layer away from the quantum dot functional layer, and patterned by laser etching / photolithography / nanoimprinting process to form a second encapsulation layer. Specifically, the thickness of the second encapsulation layer is 100nm to 20000nm, and its material includes any one or any combination of PMMA (polymethyl methacrylate), polyimide, polycarbonate, epoxy resin, polyethylene (Polyethylene, PE), polyacrylate (Polyacrylate, PA), and PET. Its manufacturing process includes organic film forming methods such as inkjet printing / spin coating / printing / lamination / evaporation.

[0076] Step S25: performing atomic layer deposition on a side of the second encapsulation layer away from the quantum dot functional layer, and patterning the second encapsulation layer using a laser etching / photolithography / nanoimprinting process to form a third encapsulation layer.

[0077] On the side of the second encapsulation layer away from the quantum dot functional layer, 5nm to 1000nm of Al2O3 is deposited by atomic layer deposition (ALD), and patterned by laser etching / photolithography / nanoimprinting process to form the third encapsulation layer. It should be noted that the temperature during deposition is 50℃ to 200℃ to avoid damage to the device.

[0078] It is understandable that when packaging, the edge keying electrodes need to be exposed to connect with the external circuit. Therefore, it is necessary to use laser etching for patterning so that the corresponding electrodes are exposed. Patterning can also be performed by nanoimprinting, photolithography (exposure, development, etching, etc.), or by printing, printing, adding a mask, etc., without specific limitation.

[0079] The infrared detection device of the present application has four layers of packaging (top electrode layer 12, first packaging layer 131, second packaging layer 132 and third packaging layer 133). The packaging structure realizes the thin film packaging structure of the detector, realizes water and oxygen protection of the detection device (pin structure), improves its service life, adapts to more severe working environments, and ensures the transmittance of infrared light.

[0080] The preparation method of the infrared detection device of the present application proposes the use of laser for patterning, which replaces the traditional patterning photolithography process (such as photoresist spin coating, exposure, development, etching and other processes), greatly reducing the production cost and the cost of wafer taping. The use of laser technology for patterning does not require mask production and corresponding photolithography, and the processing efficiency is greatly improved. It takes into account both water and oxygen barrier and light transmission properties, and the multi-layer structure can increase the transmittance of infrared light according to its NK value (thin film optical parameters, N value is refractive index, K value is extinction coefficient) and thickness and other parameters.

[0081] The algorithm and display provided herein are not inherently related to any particular computer, virtual system or other device. Various general purpose systems can also be used together with the teachings based on this. According to the above description, it is obvious that the structure required for constructing such systems. In addition, the application is not directed to any specific programming language either. It should be understood that various programming languages ​​can be utilized to realize the content of the application described herein, and the description of the specific language above is for the purpose of disclosing the best mode of implementation of the application.

[0082] In the description provided herein, a large number of specific details are described. However, it is understood that the embodiments of the present application can be practiced without these specific details. In some instances, well-known methods, structures and techniques are not shown in detail so as not to obscure the understanding of this description.

[0083] Similarly, it should be understood that in order to streamline the present disclosure and assist in understanding one or more of the various aspects of the application, in the above description of exemplary embodiments of the present application, the various features of the present application are sometimes grouped together into a single embodiment, figure, or description thereof.

[0084] Those skilled in the art will appreciate that the modules in the device in the embodiment can be adaptively changed and arranged in one or more devices different from the embodiment. The modules or units or components in the embodiment can be combined into one module or unit or component, and in addition they can be divided into multiple submodules or subunits or subcomponents. Except that at least some of such features and / or processes or units are mutually exclusive, all features disclosed in this specification (including abstracts and drawings) and all processes or units of any method or device disclosed in this manner can be combined in any combination. Unless otherwise explicitly stated, each feature disclosed in this specification (including accompanying abstracts and drawings) can be replaced by alternative features that provide the same, equivalent or similar purposes.

[0085] Furthermore, those skilled in the art will appreciate that although some embodiments herein include certain features included in other embodiments but not other features, the combination of features from different embodiments is meant to be within the scope of the present application and to form different embodiments.

[0086] It should be noted that the above embodiments illustrate the present application rather than limit the present application. Any reference symbol between brackets should not be constructed as a limitation to the present application. The word "comprising" does not exclude the existence of components or steps not listed in the present application. The word "one" or "an" before a component does not exclude the existence of multiple such components. The present application can be implemented by means of hardware including several different components and by means of a suitably programmed computer. In the embodiments in which several devices are listed, several of these devices can be embodied by the same hardware item. The use of the words first, second, and third, etc. does not indicate any order. These words can be interpreted as names.

Claims

1. An infrared detection device, characterized in that: include: Quantum dot functional layer; A top electrode layer is disposed on the surface of the quantum dot functional layer, wherein the top electrode layer is used to protect the quantum dot functional layer from being corroded by water and oxygen.

2. The infrared detection device according to claim 1, characterized in that: The top electrode layer is made of a light-transmitting and waterproof material.

3. The infrared detection device according to claim 2, characterized in that: The top electrode layer is an indium tin oxide film.

4. The infrared detection device according to claim 1, characterized in that: The infrared detection device also includes: The encapsulation layer is arranged on a side of the top electrode layer away from the quantum dot functional layer, and is used to protect the quantum dot functional layer from being corroded by water and oxygen.

5. The infrared detection device according to claim 4, characterized in that: The encapsulation layer comprises: A first encapsulation layer is disposed on a side of the top electrode layer away from the quantum dot functional layer; A second encapsulation layer is disposed on a side of the first encapsulation layer away from the quantum dot functional layer; The third packaging layer is arranged on a side of the second packaging layer away from the quantum dot functional layer.

6. The infrared detection device according to claim 5, characterized in that: The first encapsulation layer and the third encapsulation layer are Al2O3 films formed by atomic layer deposition; The second encapsulation layer is a transparent organic film.

7. The infrared detection device according to claim 1, characterized in that: The quantum dot functional layer includes, in order from the direction away from the top electrode layer to the direction close to the top electrode layer: Bottom electrode layer, electron blocking layer, p-type layer, active layer, electron transport layer, strong n-type layer.

8. A method for preparing an infrared detection device, characterized in that: include: preparing the quantum dot functional layer; An indium tin oxide film is sputtered on the surface of the quantum dot functional layer by a magnetron sputtering method, and the indium tin oxide film is patterned by a laser etching / photolithography / nanoimprinting process to form a top electrode layer; wherein the top electrode layer is used to protect the quantum dot functional layer from water and oxygen corrosion.

9. The preparation method according to claim 8, characterized in that: The method further comprises: Performing atomic layer deposition on a side of the top electrode layer away from the quantum dot functional layer, and patterning the top electrode layer using a laser etching / photolithography / nanoimprinting process to form a first encapsulation layer; An organic thin film layer is formed on a side of the first encapsulation layer away from the quantum dot functional layer by using inkjet printing / spin coating / printing / lamination / evaporation technology, and patterned by using laser etching / photolithography / nanoimprinting process to form a second encapsulation layer; Atomic layer deposition is performed on a side of the second encapsulation layer away from the quantum dot functional layer, and patterning is performed using a laser etching / photolithography / nanoimprinting process to form a third encapsulation layer.

10. The preparation method according to claim 8, characterized in that: The step of preparing the quantum dot functional layer comprises: providing a substrate; Sputtering an indium tin oxide film on the surface of the substrate by a magnetron sputtering method, and patterning the indium tin oxide film by a laser etching process to form a bottom electrode layer; An electron blocking layer, a p-type layer, an active layer, an electron transport layer, and a strong n-type layer are sequentially arranged on the bottom electrode layer; Wherein, the top electrode layer is arranged on a side of the strong n-type layer away from the bottom electrode layer.

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