Light-emitting transistor device and gas sensor

Abstract

The invention discloses a light-emitting transistor device and a gas sensor, and relates to the technical field of light-emitting transistors, and the light-emitting transistor device comprises a first electrode pair, a light-emitting transistor body and a second electrode pair which are sequentially arranged from top to bottom; the first electrode pair and the second electrode pair comprise source electrodes and drain electrodes; the source electrode and the drain electrode are arranged at the two ends of the light-emitting transistor body at intervals; in the working process, the light-emitting area is controlled by regulating and controlling the voltage of the source electrode and the drain electrode, electric field distribution can be controlled more accurately, modulation of the light-emitting performance is achieved, and therefore key parameters such as the light-emitting efficiency, the brightness and the service life of a light-emitting transistor device are directly influenced.

Description

Technical Field

[0001] The present application relates to the technical field of light-emitting transistors, and in particular to a light-emitting transistor device and a gas sensor. Background Art

[0002] Organic optoelectronic devices, such as organic light-emitting diodes (OLEDs), organic photovoltaics (OPVs), and organic field-effect transistors (OFETs), have long garnered significant attention from both the scientific and industrial communities due to their diverse range of organic materials, low cost, availability, large-scale fabrication, and compatibility with flexible substrates. Currently, OLEDs, with their advantages of fast response time, wide color gamut, low cost, and flexible processing, have reached commercialization and are being successfully applied in display devices such as mobile phones, computers, televisions, medical devices, and augmented reality electronics.

[0003] As a switch for integrated circuits and active active drive matrices, OFETs have the advantages of low cost, low temperature and large area preparation, and flexibility, so they have attractive development prospects. After nearly 30 years of development, the mobility of OFETs has increased by 5 orders of magnitude. The mobility of many high-performance OFETs reported so far has exceeded 10 cm 2 V -1 s -1 , making the performance of OFETs meet the needs of a wider range of applications.

[0004] The Organic Light-Emitting Field Effect Transistor (OLEFET) is a new functional device that combines the luminescence characteristics of OLEDs with the switching characteristics of OFETs. It theoretically provides a new device structure for studying the transport characteristics of carriers and the luminescence theory of excitons, which is of great scientific research significance. At the same time, due to its high current density and low metal electrode absorption loss, OLEFET is an ideal structure for constructing electrically pumped organic lasers. In terms of application, compared with flat-panel display technology based on OFET-driven OLEDs, flat-panel display technology based on OLEFETs has a simpler process and higher integration. It is expected to significantly reduce panel production costs, improve yield and overall panel performance, and is therefore regarded as a strong competitor for the next generation of flat-panel display technology. However, the current OLEFET devices have weak luminescence intensity and low luminescence efficiency, and the device performance cannot meet the requirements of practical applications. Summary of the Invention

[0005] The purpose of this application is to provide a light-emitting transistor device and a gas sensor that can more accurately control the electric field distribution and achieve modulation of the light-emitting performance, thereby directly affecting key parameters such as the light-emitting efficiency, brightness, and life of the light-emitting transistor device.

[0006] To achieve the above objectives, this application provides the following solutions:

[0007] In a first aspect, the present application provides a light-emitting transistor device, comprising a first electrode pair, a light-emitting transistor body, and a second electrode pair, arranged sequentially from top to bottom;

[0008] The first electrode pair and the second electrode pair include a source electrode and a drain electrode; the source electrode and the drain electrode are spaced apart and arranged at two ends of the light-emitting transistor body; during operation, the light-emitting area is controlled by regulating the voltage of the source electrode and the drain electrode;

[0009] The light emitting transistor body includes a first charge injection layer, a first charge transport layer, a first light emitting layer, a dielectric layer, a second light emitting layer, a second charge transport layer and a second charge injection layer which are sequentially arranged from top to bottom.

[0010] Optionally, the thickness of the first light-emitting layer and the second light-emitting layer is 10-50 nm.

[0011] Optionally, the electrode materials of the source and the drain include aluminum, gold, silver and copper.

[0012] Optionally, the thickness of the source electrode and the drain electrode is 10-100 nm.

[0013] Optionally, a distance between the source electrode and the drain electrode in the first electrode pair or the second electrode pair is 10 to 2000 nm.

[0014] In a second aspect, the present application provides a gas sensor, which includes a sensor body and the above-mentioned light-emitting transistor device.

[0015] Optionally, the sensor body includes transparent glass, a fluorescent dye layer and a photodetector; the transparent glass serves as a substrate; the fluorescent dye layer is used to receive light emitted by the light-emitting transistor device according to any one of claims 1 to 5; and the photodetector is used to receive the light signal generated by the fluorescent dye layer.

[0016] Optionally, the fluorescent dye layer is composed of a single layer or multiple layers of a compound containing a benzene ring or a heterocycle and having a conjugated double bond.

[0017] Optionally, the thickness of the fluorescent dye layer is 10-100 nm.

[0018] Optionally, the transparent glass has a thickness of 100 to 1000 μm.

[0019] According to the specific embodiments provided in this application, this application discloses the following technical effects:

[0020] The present application provides a light-emitting transistor device and a gas sensor. By introducing a source-drain electrode pair, a light-emitting transistor device with a controllable light-emitting area using a four-electrode structure is obtained. An additional electrode is introduced on the basis of OLEFET to realize an organic light-emitting device with four-terminal electrodes, so that the injection and transmission of holes and electrons in the OLEFET device are balanced, the exciton generation efficiency is high, and the electric field distribution can be controlled more accurately to achieve modulation of the light-emitting performance, thereby directly affecting the key parameters of the device such as luminous efficiency, brightness, and life. In addition, the use of multiple light-emitting layers can realize colorful display in a single device, improve the integration of the device, and make the volume smaller. Therefore, studying the electric field modulation mechanism and optoelectronic performance of the organic light-emitting transistor with four-terminal electrodes is a very meaningful research work. A dual-source-drain device (a dual-source-drain device refers to the source and drain in the first light-emitting layer and the second light-emitting layer) and multiple light-emitting layers are used to realize colorful light emission of a single device. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments. 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 creative work.

[0022] Figure 1 This is a schematic structural diagram of a light-emitting transistor device provided in Example 1 of the present application. DETAILED DESCRIPTION

[0023] The following will be combined with the drawings in the embodiments of this application to clearly and completely describe the technical solutions in the embodiments of this application. Obviously, the embodiments described are only part of the embodiments of this application, not all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of this application.

[0024] In order to make the above-mentioned purposes, features and advantages of the present application more obvious and easy to understand, the present application is further described in detail below with reference to the accompanying drawings and specific implementation methods.

[0025] Example 1.

[0026] This embodiment provides a light-emitting transistor device (hereinafter referred to as an OLEFET device), including a first electrode pair, a light-emitting transistor body, and a second electrode pair arranged in sequence from top to bottom; the first electrode pair and the second electrode pair include a source and a drain; the source and the drain are arranged at intervals at both ends of the light-emitting transistor body; during operation, the light-emitting area is controlled by regulating the voltage of the source and the drain.

[0027] The light-emitting transistor device consists of four electrodes, two of which are located on one side of the light-emitting transistor body, forming a first electrode pair, and the other two electrodes are located on the other side of the light-emitting transistor body, forming a second electrode pair. The light-emitting transistor device containing four electrodes can control the light-emitting area by regulating the voltage of the four electrodes.

[0028] The source and drain electrodes are made of materials including aluminum, gold, silver, and copper, with a thickness of 10 to 100 nm. The spacing between two electrodes on the same side, i.e., the spacing between the source and drain electrodes in the first electrode pair or the second electrode pair, is 10 to 2000 nm.

[0029] The light emitting transistor body includes a first charge injection layer, a first charge transport layer, a first light emitting layer, a dielectric layer, a second light emitting layer, a second charge transport layer and a second charge injection layer which are sequentially arranged from top to bottom.

[0030] like Figure 1 As shown, the light-emitting transistor device is provided with a first electrode pair, a first charge injection layer CIL-1, a first charge transport layer CTL-1, a first light-emitting layer EML-1, a dielectric layer (Dielectric Layer), a second light-emitting layer EML-2, a second charge transport layer CTL-2, a second charge injection layer CIL-2, and a second electrode pair. The first electrode pair includes a first source electrode S1 (Source 1) and a first drain electrode D1 (Drain 1). The second electrode pair includes a second source electrode S2 (Source 2) and a second drain electrode D2 (Drain 2).

[0031] The function of the charge injection layer is to transfer electrons (or holes) from the anode (or cathode) to the next layer of material, thereby realizing charge injection. For example, the function of the first charge injection layer CIL-1 is to transfer electrons from the first electrode pair to the first charge transport layer CTL-1, and the function of the second charge injection layer CIL-2 is to transfer electrons from the second electrode pair to the second charge transport layer CTL-2. The function of the charge transport layer is to promote effective charge transfer and migration between the charge transport layer and the adjacent layer. The function of the dielectric layer is to provide an insulating barrier for the transistor gate.

[0032] This embodiment mainly studies the carrier transport mechanism and electric field regulation mechanism of an organic light-emitting transistor based on a four-terminal electrode, looking for new devices to solve the problems of weak luminous intensity and low luminous efficiency of traditional OLEFETs, and in-depth research on electric field regulation and photoelectric mechanisms will help achieve full colorization of a single device. This embodiment studies the effect of channel length on the electric field regulation mechanism by changing the channel length, the thickness of the organic material, and the carrier mobility. Then, the luminous area and photoelectric characteristics of the device are analyzed. Based on the luminous area and luminous color of the device, the carrier binding area in the device is inferred, thereby understanding the electric field modulation mechanism of the device. Finally, based on this electric field modulation mechanism, a dual source-drain device and a multi-light-emitting layer are used to achieve colorful luminescence of a single light-emitting transistor device.

[0033] 1. Develop a dual-source-drain electrode stacked OLEFET structure, and achieve a breakthrough improvement in luminous brightness through a dual-light-emitting layer stacked design: This embodiment is based on the asymmetric electrode three-layer OLEFET structure, and constructs a dual-source-drain four-terminal electrode structure by introducing an additional light-emitting layer. Key parameters of this structure, such as the channel length (referring to the physical length of the conductive channel between the source (S) and the drain (D), the thickness of the light-emitting layer and the charge transfer layer, the electrode and dielectric layer (insulating layer) materials, etc., are systematically optimized to achieve the optical superposition effect of the dual light-emitting layers and prepare a stacked OLEFET device with full-color luminescence capability. On this basis, the electric field modulation characteristics and optoelectronic performance of the prepared device are deeply explored, covering the regulatory effect of the channel length on TFT performance, the injection and transport mechanism of carriers in the four-terminal electrode, and the optical superposition mechanism of the dual light-emitting layer, with a special focus on the precise control mechanism of the light-emitting area and the optimization of the response characteristics of the stacked electrode device.

[0034] Optimize the thickness of the light-emitting layer, charge transport layer, and charge injection layer. For example, the thickness of the first and second light-emitting layers can be 10-50 nm, the thickness of the charge injection layer can be 2-20 nm, and the thickness of the charge transport layer can be 2-20 nm.

[0035] 2. Photoelectric Performance Simulation and Structural Optimization of Layered OLEFET Devices: Prepare an organic light-emitting diode (OLED) device with a four-terminal electrode structure and systematically study its electric field modulation mechanism, including the effect of the electric field on carrier injection, transport, and recombination processes. The project is expected to investigate the electric field modulation mechanism of the four-terminal OLED device, thereby achieving fine control of the electric field modulation and optimizing the optoelectronic performance of this structural device. Using electrical simulation, analyze the carrier injection and transport mechanisms of the four-terminal electrode, and optimize the transport layer material and thickness to achieve balanced carrier injection. Through photoelectric performance simulation, study the luminescence performance of the OLED device under different bias conditions, and achieve superposition of luminescence from the dual-light-emitting layer.

[0036] Example 2.

[0037] This embodiment provides a gas sensor, including a sensor body and the light-emitting transistor device described in Embodiment 1.

[0038] The sensor body comprises transparent glass, a fluorescent dye layer, and a photodetector. The transparent glass serves as a substrate. The fluorescent dye layer is configured to receive light emitted by the light-emitting transistor device described in Example 1. The photodetector receives the light signal generated by the fluorescent dye layer. The gas sensor can detect both gas concentration and type. The fluorescent dye is excited by the blue light stacked OLEFET to emit light. This light signal, influenced by gas concentration and type, produces intensity and phase variations, which are then received by the photodetector to detect gas concentration and type.

[0039] Research on intelligent sensing based on stacked OLEFET devices: Leveraging the structural advantages of the stacked dual-light-emitting layer, and combining sensing and luminescence properties, a gas sensor with luminescence functionality was fabricated. Simultaneously, key parameters such as electrode spacing and sensitive layer thickness were optimized to improve the gas sensor's response speed and sensitivity, enabling it to promptly capture even small changes in gas concentration. During the gas detection performance testing and application phase, the fabricated stacked gas sensor will undergo comprehensive performance testing, including indicators such as response time, recovery time, detection limit, and selectivity, to ensure that the sensor's performance meets expectations. Furthermore, due to its unique dual-active layer structure, a single device can detect different types of gases.

[0040] The fluorescent dye layer is composed of a single layer or multiple layers of compounds containing a benzene ring or a heterocyclic ring and having a conjugated double bond. The fluorescent dyes (compounds) include acid eosin, fluorescent yellow, mercurochrome, and disperse dyes.

[0041] The thickness of the fluorescent dye layer is 10 to 100 nm, for example, 10 nm, 20 nm, 30 nm, 40 nm, 50 nm, 60 nm, 70 nm, 80 nm, 90 nm or 100 nm, but is not limited to the listed values. Other values ​​not listed within the range are also applicable.

[0042] The transparent glass is made of an organic polymer or an inorganic small molecule material; preferably, the organic polymer may be polypropylene, polycarbonate, polyvinyl chloride, polyethylene, polyethylene terephthalate, polymethyl methacrylate or polystyrene; and the inorganic small molecule material may be silicon dioxide or silicon perborate.

[0043] The thickness of the transparent glass is 100 to 1000 μm; for example, it can be 100 μm, 200 μm, 300 μm, 400 μm, 500 μm, 600 μm, 700 μm, 800 μm, 900 μm or 1000 μm, but is not limited to the listed values. Other values ​​not listed within the range are also applicable.

[0044] The red light emission wavelength of the stacked OLEFET device (i.e., light-emitting transistor device) is 625-740nm; for example, it can be 625nm, 640nm, 650nm, 670nm, 680nm, 690nm, 700nm, 710nm, 720nm, 730nm or 740nm, etc., but is not limited to the listed values, and other values ​​not listed within this range are also applicable.

[0045] The blue light emission wavelength of the stacked OLEFET device is 400-480nm; for example, it can be 400nm, 410nm, 420nm, 430nm, 440nm, 450nm, 460nm, 470nm or 480nm, but is not limited to the listed values. Other values ​​not listed within the range are also applicable.

[0046] The gases detected by the gas sensor include environmental quality-related gases and human health-indicative gases; preferably, the environmental quality-related gases include carbon dioxide, hydrogen, ammonia, hydrogen sulfide, sulfur dioxide, nitrogen dioxide, etc.; preferably, the human health-indicative gases include ammonia, nitric oxide, oxygen, carbon dioxide, etc.

[0047] The mechanism by which gas sensors detect gas is that the excitation luminescence of fluorescent dyes is affected by the concentration and type of gas, resulting in changes in light intensity and phase.

[0048] This embodiment has at least the following beneficial effects: (1) The gas detector provided by this embodiment is small in size, functionally integrated, and low in cost; (2) The gas sensor provided by this embodiment can realize the detection of different types of gases using a single light-emitting transistor device.

[0049] As a specific implementation of this embodiment, a process for fabricating a gas sensor using a light-emitting transistor device is provided. The gas sensor fabrication method includes the following steps: forming a fluorescent dye layer thin film on one side of transparent glass near a photodetector opening, and forming a light-emitting transistor device on the other side of the transparent glass. The fluorescent dye layer has a thickness of 10 to 100 nm, and the transparent glass has a thickness of 100 to 1000 μm. A photodetector is then placed at the center axis of the light-emitting transistor device.

[0050] In a specific example, a preparation process for realizing sulfur dioxide and carbon monoxide gas sensors using blue and red light from a light-emitting transistor device is provided. The preparation method comprises the following steps: preparing a fluorescent dye layer on one side of transparent glass, wherein the transparent glass is composed of polymethyl methacrylate and has a thickness of 500 μm, and the fluorescent dye layer is a double-layer composite film of acid eosin and fluorescent yellow and has a thickness of 50 nm; preparing a light-emitting transistor device on the other side of the transparent glass, wherein the blue light emission wavelength of the light-emitting transistor device is 420 nm, and the red light emission wavelength of the light-emitting transistor device is 640 nm. The concentrations of sulfur dioxide and carbon monoxide gases can be detected by detecting changes in the intensity of the excitation light signal using a photodetector.

[0051] Provided is a preparation process for realizing nitric oxide and hydrogen sulfide gas sensors using blue and red light from a light-emitting transistor device. The preparation method is identical to the detection process of the sulfur dioxide and carbon monoxide gas sensors described above, except for the difference in the emission wavelength of the light-emitting transistor device.

[0052] The technical features of the above embodiments can be combined arbitrarily. To make the description concise, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0053] This document uses specific examples to illustrate the principles and implementation methods of this application. The description of the above examples is only intended to help understand the method and core concept of this application. At the same time, for those skilled in the art, based on the concept of this application, there may be changes in the specific implementation methods and application scope. In summary, the content of this specification should not be understood as limiting this application.

Claims

1. A light-emitting transistor device, characterized in that: The light emitting transistor device comprises a first electrode pair, a light emitting transistor body and a second electrode pair arranged in sequence from top to bottom; The first electrode pair and the second electrode pair include a source electrode and a drain electrode; the source electrode and the drain electrode are spaced apart and arranged at two ends of the light emitting transistor body; During operation, the light-emitting area is controlled by regulating the voltage of the source and drain electrodes; The light emitting transistor body includes a first charge injection layer, a first charge transport layer, a first light emitting layer, a dielectric layer, a second light emitting layer, a second charge transport layer and a second charge injection layer which are sequentially arranged from top to bottom.

2. The light-emitting transistor device according to claim 1, wherein: The thickness of the first light-emitting layer and the second light-emitting layer is 10-50 nm.

3. The light-emitting transistor device according to claim 1, wherein: The electrode materials of the source electrode and the drain electrode include aluminum, gold, silver and copper.

4. The light emitting transistor device according to claim 1, wherein: The thickness of the source electrode and the drain electrode is 10-100 nm.

5. The light emitting transistor device according to claim 1, wherein: The distance between the source electrode and the drain electrode in the first electrode pair or the second electrode pair is 10 to 2000 nm.

6. A gas sensor, characterized in that: The gas sensor comprises a sensor body and the light-emitting transistor device according to any one of claims 1 to 5.

7. The gas sensor according to claim 6, characterized in that The sensor body includes transparent glass, a fluorescent dye layer and a photodetector; the transparent glass serves as a substrate; the fluorescent dye layer is used to receive light emitted by the light-emitting transistor device according to any one of claims 1 to 5; and the photodetector is used to receive the light signal generated by the fluorescent dye layer.

8. A gas sensor according to claim 7, characterized in that: The fluorescent dye layer is composed of a single layer or multiple layers of compounds containing a benzene ring or a heterocycle and having conjugated double bonds.

9. A gas sensor according to claim 7, characterized in that: The thickness of the fluorescent dye layer is 10-100 nm.

10. A gas sensor according to claim 7, characterized in that: The transparent glass has a thickness of 100 to 1000 μm.

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