Photo-controllable active adaptive organic transistor, preparation method and application

Abstract

The application relates to a light-controlled active adaptive organic transistor, a preparation method and application, belongs to the field of organic bioelectronics, and is used for solving the technical problem that the design of integrated sensors and logic circuits causes the complexity of a sensor control circuit. The light-controlled active adaptive organic transistor comprises a semiconductor intermediate layer; the semiconductor intermediate layer comprises a light response layer and a carrier trapping layer; the light response layer is used for sensing a light signal and generating photo-generated carriers; the carrier trapping layer is used for trapping the photo-generated carriers; and the semiconductor intermediate layer is used for adjusting the decay time constant of output current of the adaptive organic transistor according to the brightness of the light signal. The technical scheme provided by the application can improve the applicability of an electronic device in simulating the vision of a biological body.

Description

Technical Field

[0001] This invention relates to the field of organic bioelectronics, specifically to a light-controlled active adaptive organic transistor, its fabrication method, and its application. Background Technology

[0002] In recent years, with the rapid development of flexible biomimetic devices and artificial intelligence, the development of new flexible electronic devices to simulate the visual adaptation behavior of organisms has great scientific significance and application prospects.

[0003] To simulate this process, people have developed various adaptive optics control systems through the design of integrated sensors and logic circuits, which are widely used in modern electronic devices. For example, mobile phone displays can actively change their display output according to different ambient brightness.

[0004] However, the design of integrated sensors and logic circuits leads to complex sensing control circuits, requiring sufficient space to set up the circuits, which reduces the applicability of electronic devices to simulate biological vision. Summary of the Invention

[0005] Based on the above analysis, the present invention aims to propose a light-controlled active adaptive organic transistor, its fabrication method, and its application, so as to improve the applicability of electronic devices to simulate biological vision.

[0006] The objective of this invention is mainly achieved through the following technical solutions:

[0007] In a first aspect, embodiments of the present invention provide a light-controlled active adaptive organic field-effect transistor, comprising: a semiconductor intermediate layer; the semiconductor intermediate layer comprising: a photosensitive layer and a carrier trapping layer;

[0008] The photosensitive layer is used to sense optical signals and generate photogenerated carriers;

[0009] The carrier trapping layer is used to trap the photogenerated carriers;

[0010] The semiconductor intermediate layer is used to adjust the decay time constant of the output current of the adaptive organic transistor according to the brightness of the optical signal.

[0011] Furthermore, the material of the carrier trapping layer includes at least one of polyvinyl alcohol, polyacrylonitrile, and phenelzine C.

[0012] Furthermore, the photosensitive layer is a bulk heterojunction, and the donor material of the bulk heterojunction includes: polythiophene system materials and pyrrolopyrrole dione materials, and the acceptor material of the bulk heterojunction includes: fullerene materials.

[0013] The donor material is specifically one of PBTTT and its derivatives, P3HT and its derivatives, DPP-DTT and its derivatives, and PDPP3T and its derivatives.

[0014] The receptor material is specifically PCBM and its derivatives.

[0015] Furthermore, the photosensitive layer is made of PDPP3T and PCBM, with a mass ratio of PDPP3T to PCBM of 1:2 to 2:1; or, the photosensitive layer is made of P3HT and PCBM, with a mass ratio of P3HT to PCBM of 1:2 to 2:1.

[0016] Furthermore, the organic field-effect transistor further includes: an organic semiconductor layer;

[0017] The organic semiconductor layer is a bulk heterojunction, and the donor material of the bulk heterojunction includes: polythiophene system materials and pyrrolopyrrole dione materials, and the acceptor material of the bulk heterojunction includes: fullerene materials.

[0018] The donor material is specifically one of PBTTT and its derivatives, P3HT and its derivatives, DPP-DTT and its derivatives, and PDPP3T and its derivatives.

[0019] The receptor material is specifically PCBM and its derivatives.

[0020] Further, the organic semiconductor layer is made of PDPP3T and PCBM, with a mass ratio of PDPP3T to PCBM of 1:2 to 2:1; or, the organic semiconductor layer is made of P3HT and PCBM, with a mass ratio of P3HT to PCBM of 1:2 to 2:1.

[0021] Furthermore, the thickness of the semiconductor intermediate layer is 10 nm to 100 nm;

[0022] The thickness of the organic semiconductor layer is 10 nm to 100 nm.

[0023] Furthermore, the organic field-effect transistor also includes a substrate, a gate electrode, a lower insulating layer, an upper insulating layer, and a source electrode and a drain electrode located on the organic semiconductor layer, wherein the substrate, gate electrode, lower insulating layer, semiconductor intermediate layer, upper insulating layer and organic semiconductor layer are arranged sequentially from bottom to top.

[0024] Furthermore, when the brightness value of the optical signal is less than 100 cd·m -2 At that time, the attenuation time constant of the optical signal is adjusted to be greater than 100s;

[0025] When the brightness value of the light signal is 10 2 cd·m-2 and 10 4 cd·m -2 During this period, the attenuation time constant of the optical signal is adjusted to be between 100s and 1s;

[0026] When the brightness value of the light signal is greater than 10 4 cd·m -2 At that time, the attenuation time constant of the optical signal is adjusted to be less than 1 second.

[0027] Secondly, embodiments of the present invention provide a method for fabricating a light-controlled active adaptive organic field-effect transistor, comprising:

[0028] Step 1. Provide a substrate and fabricate a gate electrode on the substrate;

[0029] Step 2. Prepare a lower insulating layer on the gate electrode;

[0030] Step 3. Fabricate a semiconductor intermediate layer on the lower insulating layer;

[0031] Step 4. Prepare an insulating layer on the semiconductor intermediate layer;

[0032] Step 5. Prepare an organic semiconductor layer on the upper insulating layer;

[0033] Step 6. Deposit source and drain electrodes on the organic semiconductor layer to obtain a light-controlled adaptive organic field-effect transistor.

[0034] Furthermore, a method for fabricating an organic field-effect transistor includes:

[0035] Step 1. After subjecting the substrate to ultrasonication with secondary water, ethanol, and acetone, rinsing, drying with nitrogen gas once, concentrated sulfuric acid / hydrogen peroxide, ultrasonication with secondary water, and drying with nitrogen gas twice, the substrate is fabricated into a gate electrode under vacuum conditions.

[0036] Step 2. Prepare a lower insulating layer on the gate electrode;

[0037] Step 3. The lower insulating layer is subjected to UV curing and vapor phase modification in sequence, and a semiconductor intermediate layer is prepared on the vapor phase modified lower insulating layer;

[0038] Step 4. An upper insulating layer is obtained on the semiconductor intermediate layer by spin coating, ultraviolet curing and heat treatment;

[0039] Step 5. Prepare an organic semiconductor layer on the upper insulating layer, wherein the organic semiconductor layer is a combination of any one of PBTTT and its derivatives, PDPP3T and its derivatives, P3HT and its derivatives, DPP-DTT and any one of PCBM and its derivatives;

[0040] Step 6. Deposit source and drain electrodes on the organic semiconductor layer to obtain a light-controlled adaptive organic field-effect transistor.

[0041] Furthermore, in step 3, the UV curing wavelength is 254 nm, and the curing time is 15 min-25 min;

[0042] Furthermore, in step 3, the semiconductor intermediate layer is obtained by spin coating at a speed of 3000 rpm to 5000 rpm; and then annealed on a hot plate at 100°C to 120°C for 1 hour to 1.5 hours.

[0043] Furthermore, the substrate temperature during spin coating is 95℃~100℃.

[0044] Further, in step 5, the organic semiconductor layer is obtained by spin coating at a speed of 3000-5000 rpm; and then annealed on a hot plate at 100-120°C for 1-1.5 hours.

[0045] Thirdly, the application of the light-controlled active adaptive organic field-effect transistor described in the first aspect or the light-controlled active adaptive organic field-effect transistor prepared by the preparation method described in the second aspect in simulating biological vision.

[0046] This invention can achieve one of the following technical effects:

[0047] 1. This invention provides a light-controlled active adaptive organic transistor (OFET) capable of simulating the visual adaptation ability of the human eye. The OFET has a semiconductor interlayer and an organic semiconductor layer, both of which are heterojunction structures. The semiconductor interlayer can sense light signals and generate photogenerated carriers. Within a preset time, it captures the photogenerated carriers in the composite insulating layer. The organic semiconductor layer then transmits the attenuated photogenerated carriers to the output terminal to simulate the visual adaptation ability of the human eye.

[0048] 2. By using an organic field-effect transistor, the visual adaptation ability of the human eye can be simulated. Compared with existing technologies, the structure for achieving this ability is simpler, increasing the applicability of electronic devices to simulate biological vision.

[0049] 3. The organic field-effect transistor of this invention has multiple operating modes depending on the brightness value of the external light source, including a slow-adaptation mode and a fast-adaptation mode. For example: Mode 1: When the brightness value of the external light source is less than 100 cd·m² -2 When the decay time constant is greater than 100s. Mode 2: When the brightness value of the external light source is 10... 2 cd·m -2 and 10 4 cd·m -2When the brightness of the external light source is greater than 104 cd·m⁻², the decay time constant is between 100 s and 1 s. Mode 3: When the brightness of the external light source is greater than 10⁴ cd·m⁻², the decay time constant is less than 1 s. Among them, Mode 1 and Mode 2 correspond to the slow adaptation mode of the human eye, and Mode 3 corresponds to the fast adaptation mode of the human eye.

[0050] Other features and advantages of the invention will be set forth in the description which follows, and will be apparent in part from the description, or may be learned by practicing the invention. The objects and other advantages of the invention may be realized and obtained by means of the structures particularly pointed out in the written description and the accompanying drawings. Attached Figure Description

[0051] The accompanying drawings are for illustrative purposes only and are not intended to limit the invention. Throughout the drawings, the same reference numerals denote the same parts.

[0052] Figure 1 This is a schematic diagram of the structure of a light-controlled active adaptive OFET provided in an embodiment of the present invention;

[0053] Figure 2 This is a schematic diagram of a photo-controlled adaptive OFET based on a silicon wafer substrate;

[0054] Figure 3 The molecular backbone structure of some of the photosensitive layer materials and organic semiconductor layer materials used in the embodiments of the present invention;

[0055] Figure 4 The transfer characteristic curves of the light-controlled active adaptive OFET in Embodiment 1 of the present invention under different light intensities are shown.

[0056] Figure 5 The in-situ response curves of the light-controlled active adaptive OFET in Embodiment 1 of the present invention to different light intensities are shown.

[0057] Figure 6 The decay time constant of the light-controlled active adaptive OFET in Embodiment 1 of the present invention under different light intensities is classified;

[0058] Figure 7 The source-drain current response curve of the light-controlled active adaptive OFET under continuous stepped illumination intensity in Embodiment 1 of the present invention;

[0059] Figure 8 This illustrates the relationship between the activation energy of electron trapping in the light-controlled active adaptive OFET and the light intensity in Embodiment 1 of the present invention.

[0060] Figure 9 The source current response curves of the light-controlled active adaptive OFET under different light intensities in Embodiment 4 of the present invention are shown.

[0061] Figure 10 This is the photocurrent characteristic curve of the light-controlled active adaptive OFET in Embodiment 5 of the present invention as light intensity increases.

[0062] Figure label:

[0063] 1 is the substrate, 2 is the gate electrode, 3 is the lower insulating layer, 4 is the semiconductor intermediate layer, 5 is the upper insulating layer, 6 is the organic semiconductor layer, 7 is the source electrode, and 8 is the drain electrode. Detailed Implementation

[0064] The preferred embodiments of the present invention will now be described in detail with reference to the accompanying drawings, which constitute a part of the present invention and are used together with the embodiments of the present invention to illustrate the principles of the present invention, but are not intended to limit the scope of the present invention.

[0065] Adaptation is the foundation of neural computation in the sensory system. Through adaptation, strong external stimuli can be converted into limited neural signals, thereby enabling information processing and compilation. Taking the human visual system as an example, the human eye, as the basic organ for perceiving external light stimuli, possesses both the function of responding to light signals and processing information. From day to night, the absolute value of light incident on the retina differs by ten orders of magnitude or more, yet the range of change in optic nerve signals does not exceed two orders of magnitude. The human eye must adjust its visual sensitivity according to external light stimuli of different intensities. This active dynamic adjustment process is reflected in the phenomenon of visual adaptation in the human eye. Through active adaptation, visual damage can be prevented, sensitivity can be adjusted, and visual resolution can be improved.

[0066] To simulate the above process, humans typically use integrated sensors and logic circuits. Taking smart display devices such as mobile phone screens as an example, the specific adjustment process is as follows:

[0067] 1. Collect ambient light intensity and mobile phone screen light intensity;

[0068] 2. Compare the ambient light intensity with the light intensity of the mobile phone screen;

[0069] 3. By comparing two light intensities using the comparison structure in the phone, a signal for adjusting the phone screen brightness is output;

[0070] 4. Based on the screen brightness adjustment signal, the screen brightness is controlled through the corresponding control circuit.

[0071] Therefore, the solution requires at least four circuits: an external light intensity acquisition circuit, a mobile phone screen light intensity acquisition circuit, a light intensity comparison circuit, and a brightness control circuit. This means that achieving simulated visual adaptation requires integrating four functions into the circuitry. Thus, the above method is more suitable for devices with relatively complete circuit functions, such as mobile phones and other electronic products. However, constructing such logic circuits consumes a lot of energy and occupies a significant amount of space, which is not conducive to large-scale device integration in the future. Furthermore, with the development of technology, users' demands for functional diversity will increase. Using at least four circuits to achieve one function consumes too many resources, hindering the realization of functional diversity.

[0072] Based on the above problems, this invention designs a novel organic field-effect transistor (OFET) such as... Figure 1 As shown, from bottom to top, it includes: a substrate 1, a gate electrode 2, a lower insulating layer 3, a semiconductor intermediate layer 4, an upper insulating layer 5, and an organic semiconductor layer 6, as well as a source electrode 7 and a drain electrode 8 located on the organic semiconductor layer 6. The gate electrode 2 is made of a metal, such as aluminum.

[0073] Organic field-effect transistors (OFETs), as three-terminal devices, have signal conversion and signal amplification functions. OFETs can utilize electric fields to modulate the charge transport properties of organic semiconductors, laying the foundation for the physicochemical regulation of bioelectronic functions; on the other hand, the flexible design characteristics of organic semiconductors also provide core material support for the construction of OFET bioelectronic devices.

[0074] In this embodiment of the invention, a semiconductor intermediate layer is provided in the organic field-effect transistor. The semiconductor intermediate layer includes a photosensitive layer and a carrier trapping layer. The photosensitive layer is a heterojunction structure used to sense optical signals and generate photogenerated carriers. The carrier trapping layer is used to trap photogenerated carriers. When the two are combined, the semiconductor intermediate layer can adjust the decay time constant of the adaptive organic transistor output current according to the brightness of the optical signal.

[0075] The heterojunction of the photosensitive layer is a bulk heterojunction, which greatly increases the interface area and is beneficial for the generation of photogenerated carriers. Its donor materials include polythiophene system materials and pyrrolopyrrole dione materials, and its acceptor materials include fullerene materials. Specifically, the donor material is one of PBTTT and its derivatives, P3HT and its derivatives, DPP-DTT and its derivatives, and PDPP3T and its derivatives; the acceptor material is PCBM and its derivatives. Preferably, the photosensitive layer is composed of PDPP3T and PCBM, with a mass ratio of PDPP3T to PCBM of 1:2 to 2:1; or the photosensitive layer is composed of P3HT and PCBM, with a mass ratio of P3HT to PCBM of 1:2 to 2:1.

[0076] In this embodiment of the invention, the material of the carrier trapping layer includes at least one of polyvinyl alcohol, polyacrylonitrile, and pyrene C.

[0077] The main chain structure of the photosensitive layer material of this invention is a conjugated system with conjugated π bonds, such as... Figure 3 As shown. Its derivatives utilize substituents to replace hydrogen atoms in the cyclic structure of the main chain. For example, one or more of the following groups—hydrocarbon, hydroxyl, carboxyl, halogen, nitro, aldehyde, cyano, sulfonic acid, and amino—can replace hydrogen atoms in the cyclic structure of the main chain. These derivatives can replace PBTTT, P3HT, DPP-DTT, PDPP3T, or PCBM as donor or acceptor materials in bulk heterojunctions.

[0078] In this embodiment of the invention, the organic field-effect transistor further includes an organic semiconductor layer. In order to realize the transport of photogenerated carriers, the organic semiconductor layer is also a bulk heterojunction. Its donor material includes polythiophene system material and pyrrolopyrrole dione material, and its acceptor material includes fullerene material.

[0079] Specifically, its donor material is one of PBTTT and its derivatives, P3HT and its derivatives, DPP-DTT and its derivatives, and PDPP3T and its derivatives; its acceptor material is PCBM and its derivatives.

[0080] Preferably, the organic semiconductor layer can be made of PDPP3T and PCBM in a 1:1 mass ratio, or of P3HT and PCBM in a 1:1 mass ratio. The semiconductor intermediate layer can be made of PBTTT and PCBM in a 1:1 mass ratio, or of P3HT and PCBM in a 1:1 mass ratio.

[0081] In this embodiment of the invention, through the combination of an organic semiconductor layer and a semiconductor intermediate layer, the organic field-effect transistor can mechanistically mimic the visual adaptation ability of the human eye. That is, by utilizing the light attenuation properties of the material, the intensity of the received light source is attenuated to a set value within a preset time. Just as when a person moves from a dark place to a bright place (such as from a movie theater to outdoors), initially they feel dazzled by the light and can hardly see anything clearly, but after a few seconds their visual sensitivity gradually decreases and they can gradually see objects clearly, this process corresponds to the light adaptation process of the human eye.

[0082] Specifically, when the luminance value of the external light source is less than 100 cd·m -2 When the decay time constant is greater than 100s. When the brightness value of the external light source is 10... 2 cd·m -2 and 10 4 cd·m -2 When the brightness value of the external light source is greater than 10, the decay time constant is between 100s and 1s.4 cd·m -2 When the decay time constant is less than 1 second, the decay time constant of the human eye can be defined as fast adaptation in the millisecond range and slow adaptation in the second range. Therefore, the above-mentioned range of decay time constants is comparable to the order of magnitude of the time for slow and fast adaptation of the human eye.

[0083] Therefore, the OFET in this embodiment of the invention can automatically select the corresponding mode according to the intensity of external light, thereby achieving visual adaptation. Compared with the prior art, the process and logic of achieving visual adaptation in this invention are simpler. Furthermore, this invention only requires one OFET to achieve the above functions, without the need to construct multiple circuits or rely on functional circuits on electronic devices. Therefore, the technical solution of this invention is applicable to devices with simple circuit structures, and thus has better applicability than the prior art. In addition, the technical solution of this invention is also applicable to various substrates, including: Pyrelin flexible substrates and silicon wafer substrates.

[0084] This invention provides a method for fabricating an organic field-effect transistor, comprising the following steps:

[0085] Step 1. Provide a substrate and fabricate a gate electrode on the substrate;

[0086] In this embodiment of the invention, before fabricating the gate electrode, the substrate is rinsed and dried multiple times, and finally the gate electrode is fabricated on the substrate under vacuum conditions. For example, the substrate is subjected to ultrasonic treatment with secondary water, ethanol, and acetone, rinsed, dried once with nitrogen, treated with concentrated sulfuric acid / hydrogen peroxide, ultrasonic treatment with secondary water, and dried again with nitrogen, and then the substrate is fabricated into a gate electrode under vacuum conditions.

[0087] Step 2. Prepare a lower insulating layer on the gate electrode.

[0088] In this embodiment of the invention, a lower insulating layer is prepared using spin coating, wherein the spin coating speed is 2000 rpm to 3500 rpm (e.g., 2100 rpm, 2200 rpm, 2300 rpm, 2400 rpm, 2500 rpm, 2600 rpm, 2700 rpm, 2800 rpm, 2900 rpm, 3100 rpm, 3200 rpm, 3300 rpm, 3400 rpm). The resulting insulating layer thickness is 100 nm to 200 nm (e.g., 110 nm, 120 nm, 130 nm, 140 nm, 150 nm, 160 nm, 170 nm, 180 nm, 190 nm). For example, polyvinyl cinnamate (PVCN) is spin-coated onto the gate electrode, wherein the concentration of PVCN is 30 mg / mL, the solvent is chlorobenzene, and the spin coating speed is 2000 to 3500 rpm. A PVCN lower insulating layer with a thickness of 100 to 200 nm is obtained by spin coating.

[0089] Step 3. Prepare a semiconductor intermediate layer on the lower insulating layer.

[0090] In this embodiment of the invention, the semiconductor intermediate layer includes a photosensitive layer and a carrier trapping layer. Therefore, the lower insulating layer is first subjected to UV curing, heating, and vapor phase modification sequentially, and the photosensitive layer is then prepared on the vapor-modified lower insulating layer using a spin-coating method. Subsequently, the carrier trapping layer is prepared on the photosensitive layer using a spin-coating method. The UV curing wavelength is 254 nm, and the curing time is 15-25 min (e.g., 16 min, 17 min, 18 min, 19 min, 20 min, 21 min, 22 min, 23 min, 24 min). The spin-coating speed is 3000 rpm to 5000 rpm (e.g., 3200 rpm, 3400 rpm, 3600 rpm, 3800 rpm, 4000 rpm, 4200 rpm, 4400 rpm, 4600 rpm, 4800 rpm).

[0091] For example, the lower insulating layer undergoes UV curing at a wavelength of 254 nm for 20 min, followed by heat treatment on a hot stage for 1 hour. Then, it is modified with octadecyltrichlorosilane (OTS) vapor phase in a vacuum oven at 120 °C for 3 h. After curing and modification, a mixed solution of P3HT and PCBM (20 mg / mL concentration, chlorobenzene solvent) is spin-coated onto the lower insulating layer at 5000 rpm. This spin-coating yields a photosensitive layer with a thickness of 50 nm, which is then annealed at 100 °C for 1 hour. Polyvinyl alcohol (PVA) is then spin-coated above the photosensitive layer to form a carrier trapping layer. The PVA solution has a concentration of 15 mg / mL, uses a 1:1 mixture of deionized water and ethanol, and is spin-coated at 5000 rpm with a thickness of 50 nm.

[0092] Step 4. Prepare an insulating layer on the semiconductor intermediate layer.

[0093] In this embodiment of the invention, an upper insulating layer is obtained on a semiconductor intermediate layer through spin coating, UV curing, and heat treatment. For example, a layer of PVCN is spin-coated on top of the obtained carrier trapping layer for surface planarization. The concentration of PVCN is 20 mg / mL, the solvent is chlorobenzene, and the spin speed is 5000 rpm, resulting in a PVCN layer with a thickness of 50 nm. Then, the PVCN is subjected to UV curing and heat treatment, and modified with OTS to obtain a PVA-PVCN composite upper insulating layer.

[0094] Step 5. Prepare an organic semiconductor layer on the upper insulating layer.

[0095] In this embodiment of the invention, an organic semiconductor layer is directly prepared on the upper insulating layer by spin coating, wherein the spin coating speed is 3000 rpm to 5000 rpm (e.g., 3200 rpm, 3400 rpm, 3600 rpm, 3800 rpm, 4000 rpm, 4200 rpm, 4400 rpm, 4600 rpm, 4800 rpm), and the substrate temperature is 90℃ to 100℃ (e.g., 91℃, 92℃, 93℃, 94℃, 95℃, 96℃, 97℃, 98℃, 99℃). For example, a mixed solution of PDPP3T and PCBM is spin-coated on the upper insulating layer at a speed of 5000 rpm, wherein the concentration of the mixed solution is 10 mg / mL, the solvent is chlorobenzene, and the substrate temperature during spin coating is 95℃, to obtain a PDPP3T semiconductor transport layer with a thickness of 40 to 70 nm.

[0096] Step 6. Deposit source and drain electrodes on the organic semiconductor layer to obtain a light-controlled adaptive organic field-effect transistor.

[0097] To illustrate the effects of the above embodiments, the present invention provides the following specific embodiments:

[0098] Example 1

[0099] 1) After ultrasonic cleaning, rinsing, and nitrogen drying of the glass substrate using secondary water, ethanol, and acetone, immerse it in a mixed cleaning solution of concentrated sulfuric acid / hydrogen peroxide (volume ratio 70% / 30%). Remove it after half an hour and continue ultrasonic cleaning with secondary water. After cleaning, dry it with a nitrogen gun. (The process is repeated in the original text.) -4 Under the condition of Pa Aluminum is deposited on the substrate at a speed of 30 nm to obtain the gate electrode;

[0100] 2) Polyvinyl cinnamate (PVCN) is spin-coated onto the patterned gate electrode obtained in step 1), wherein the concentration of PVCN is 30 mg / mL, the solvent is chlorobenzene, and the spin speed is 3500 rpm. A PVCN underlayer insulating layer with a thickness of 100 nm is obtained by spin-coating.

[0101] 3) The PVCN lower insulation layer obtained in step 2) is subjected to ultraviolet curing treatment. The ultraviolet curing wavelength is 254nm and the curing time is 20min. It is then heat-treated on a hot stage for 1 hour. After that, octadecyltrichlorosilane (OTS) vapor phase modification is performed in a vacuum oven at 120℃ for 3h.

[0102] 4) Spin-coat a mixed solution of P3HT and PCBM onto the cured and modified lower insulating layer obtained in step 3) (see Figure 3The concentration of the P3HT and PCBM mixed solution was 20 mg / mL, the solvent was chlorobenzene, and the rotation speed was 3000–5000 rpm. A bulk heterojunction composed of P3HT and PCBM, i.e., a photosensitive layer, with a thickness of 30–100 nm, was obtained by spin coating and then annealed at 100 °C for 1 hour on a hot plate.

[0103] 5) Spin-coat polyvinyl alcohol (PVA) onto the photosensitive layer obtained in step 4), wherein the concentration of the PVA solution is 15 mg / mL, the solvent is a 1:1 volume ratio of deionized water / ethanol mixed solvent, and the spin speed is 5000 rpm, to obtain a carrier trapping layer with a thickness of 50 nm. Then, spin-coat a layer of PVCN on the obtained PVA for surface planarization, wherein the concentration of PVCN is 20 mg / mL, the solvent is chlorobenzene, and the spin speed is 5000 rpm, to obtain a PVCN layer with a thickness of 50 nm. Then, the PVCN is subjected to UV curing and heat treatment, and modified with OTS, the method and steps are the same as in step 3), to obtain a PVA-PVCN composite insulating layer;

[0104] 6) Spin-coat a mixed solution of PDPP3T and PCBM onto the upper insulating layer obtained in step 5) at a rotation speed of 5000 rpm. The concentration of the mixed solution of PDPP3T and PCBM is 10 mg / mL, the mass ratio of the two substances is 1:1, the solvent is chlorobenzene, the substrate temperature during spin-coating is 95℃, and a PDPP3T organic semiconductor layer with a thickness of 40 nm is obtained.

[0105] 7) Deposit source and drain electrodes onto the organic semiconductor layer obtained in step 6), and then deposit them under a vacuum of 7 × 10⁻⁴ Pa. Gold was deposited onto the substrate at a speed of 12 nm.

[0106] The structure of the device is as follows Figure 1 As shown, from bottom to top, it consists of a substrate 1, a gate electrode 2, a lower insulating layer 3, a photoresponsive semiconductor intermediate layer 4, an upper insulating layer 5, an organic semiconductor layer 6, and a source electrode 7 and a drain electrode 8 located on the organic semiconductor layer 6, which is a photo-adaptive OFET.

[0107] The electrical performance of the light-controlled adaptive OFET obtained in Example 1 was tested, and the results are as follows:

[0108] 1) Transfer characteristic curve test:

[0109] The transfer characteristic curves under different light intensities are as follows: Figure 4 As shown, the intensity of visible light is 10 2 cd m -2Above certain light intensities, the device begins to exhibit hysteresis, and as the external light intensity increases, the hysteresis of the transfer characteristic curve gradually increases, corresponding to an increasingly rapid internal electron trapping process within the composite insulating layer.

[0110] 2) Pulse light response test:

[0111] The output signal of the source current under pulse light of different intensities is as follows: Figure 5 As shown, the source current decays controllably when the light intensity remains constant. An exponential fit on the decay yields the decay time constant for different light intensities, as shown below. Figure 6 As shown, the decay time constant is adjustable in the range of 1000 to 0.1s, which is comparable to the decay rate of human visual receptors in different scenarios. This indicates that the light-controlled adaptive OFET obtained above can effectively simulate the human visual adaptation phenomenon.

[0112] 3) Device response test to a series of stepped light intensities:

[0113] Human vision possesses the ability to adjust and adapt to changes in the external environment in real time, reflected in its dynamic response to changes in external stimulus signals. A series of in-situ response tests with stepped light intensity were conducted on the obtained light-controlled adaptive OFET, and the test results are as follows: Figure 7 As shown. When the light intensity increases from 1 cd m -2 Increased to 10 cd m -2 At that time, the photoresponse increases with increasing light intensity in a gradient manner, and when the light intensity further increases to 10... 2 cd m -2 At that time, the in-situ response curve began to show a certain degree of decay, and the decay rate gradually accelerated as the light intensity continued to increase, reflecting the dynamic matching characteristics of the light-controlled active adaptive OFET to the changing brightness background.

[0114] In this embodiment of the invention, light irradiating the photosensitive layer generates photogenerated carriers, converting light energy into electrical energy. At this point, it is necessary to rapidly capture these photogenerated carriers within the insulating layer to achieve a light signal attenuated to a certain level at the drain output of the organic field-effect transistor. The speed at which photogenerated carriers are captured depends on the activation energy required for electron capture within the insulating layer. A lower activation energy makes it easier for photogenerated carriers in the insulating layer to be captured by the semiconductor intermediate layer, while also resulting in a smaller decay time constant.

[0115] Specifically, such as Figure 8 As shown, the activation energy for electron trapping in the insulating layer decreases with increasing light intensity. Therefore, the greater the light intensity, the lower the activation energy required for electron trapping within the insulating layer, and the easier it is for photogenerated carriers to be trapped by the carrier trapping layer, ultimately resulting in a smaller decay time constant. Therefore, in this embodiment of the invention, when the brightness value of the external light source is less than 100 cd·m², -2When the attenuation time constant is greater than 100s; when the brightness value of the external light source of the optical signal is within 10... 2 cd·m -2 and 10 4 cd·m -2 When the light intensity of the external light source is greater than 10, the decay time constant is between 100s and 1s. 4 cd·m -2 At that time, the decay time constant is less than 1 second.

[0116] The effect of the above method is similar to the visual adaptation behavior of the human eye under different light intensities. Therefore, the technical solution provided in the embodiments of the present invention can simulate the visual adaptation behavior of the human eye under different light intensities.

[0117] Example 2

[0118] Following the method of Example 1, the substrate in step 1) is replaced with a flexible substrate of Piriton C, specifically Piriton C, which is prepared by chemical vapor deposition with a thickness of 50 nm, to obtain the flexible light-controlled adaptive OFET provided by the present invention.

[0119] The structure of this device is the same as that obtained in Example 1, the only difference being the substrate.

[0120] This flexible, light-controlled adaptive OFET is extremely lightweight and has excellent flexibility and conformal attachment properties.

[0121] Example 3

[0122] 1) Using a silicon wafer as a substrate, a heavily doped silicon wafer with 50nm silicon dioxide thermally grown on its surface is sequentially ultrasonicated with secondary water, ethanol, and acetone, rinsed, and dried with nitrogen. Then, it is immersed in hot piranha washing solution (70% concentrated sulfuric acid and 30% hydrogen peroxide) for 30 minutes. The silicon wafer is then removed and rinsed with secondary water. After that, OTS vapor phase modification is performed in a vacuum oven at 120°C for 3 hours to obtain the gate electrode and the lower insulating layer.

[0123] 2) A mixed solution of P3HT and PCBM was spin-coated onto the OTS-modified silicon wafer obtained in step 1). The concentration of the mixed solution of P3HT and PCBM was 20 mg / mL, the solvent was chlorobenzene, and the spin speed was 5000 rpm. A bulk heterojunction composed of P3HT and PCBMT, i.e., a photosensitive layer, with a thickness of 50 nm, was obtained by spin-coating and then annealed at 100 °C for 1 hour on a hot plate.

[0124] 3) Spin-coat polyvinyl alcohol (PVA) onto the photosensitive layer obtained in step 2), wherein the concentration of the PVA solution is 15 mg / mL, the solvent is a 1:1 volume ratio of deionized water / ethanol mixed solvent, and the spin speed is 5000 rpm, to obtain a carrier trapping layer with a thickness of 50 nm. Then, spin-coat a layer of PVCN on the obtained PVA for surface planarization, wherein the concentration of PVCN is 20 mg / mL, the solvent is chlorobenzene, and the spin speed is 5000 rpm, to obtain a PVCN layer with a thickness of 50 nm. Then, the PVCN is subjected to UV curing and heat treatment, and modified with OTS, the method and steps are the same as in step 1), to obtain a PVA-PVCN composite insulating layer;

[0125] 4) Spin-coat a mixed solution of PDPP3T and PCBM onto the upper insulating layer obtained in step 3) at a rotation speed of 5000 rpm. The concentration of the mixed solution of PDPP3T and PCBM is 10 mg / mL, the solvent is chlorobenzene, and the substrate temperature during spin-coating is 95℃. A PDPP3T organic semiconductor layer with a thickness of 40 nm is obtained.

[0126] 5) Deposit the source and drain electrodes onto the organic semiconductor layer obtained in step 4) under a vacuum of 7 × 10⁻⁶. -4 Under the condition of Pa Gold was deposited onto the substrate at a speed of 12 nm.

[0127] The structure of the device is as follows Figure 2 As shown, from bottom to top, it consists of a gate electrode 2, a lower insulating layer 3, a photoresponsive semiconductor intermediate layer 4, an upper insulating layer 5, an organic semiconductor layer 6, and a source electrode 7 and a drain electrode 8 located on the organic semiconductor layer 6. Among these, Figure 2 The gate electrode 2 is made of silicon or silicon dioxide.

[0128] This adaptive OFET uses a silicon wafer as a substrate, which is beneficial for integration with traditional inorganic devices. The resulting light-controlled adaptive OFET is used to test its light-controlled adaptive characteristics.

[0129] Example 4

[0130] Following the method of Example 1, the materials for preparing the organic semiconductor layer in step 6) were replaced with DPP-DTT and PCBM in a 1:1 mass ratio. A 10 mg / ml chlorobenzene solution was prepared. The DPP-DTT:PCBM layer was prepared by spin coating at a substrate temperature of 95°C, resulting in a DPP-DTT:PCBM organic semiconductor layer with a thickness of 40 nm. The structure of this device is the same as that obtained in Example 1, except for the different materials used in the organic semiconductor layer. Its photoresponse test results are as follows: Figure 9 As shown.

[0131] Example 5

[0132] Following the method of Example 1, the materials for preparing the photosensitive layer in step 2) were replaced with PBTTT and PCBM in a 1:1 mass ratio, and a 10 mg / ml chlorobenzene solution was prepared. The photosensitive layer was prepared by spin coating at a substrate temperature of 95°C, and the thickness of the photosensitive layer was 50 nm. The structure of this device is the same as that obtained in Example 1, except that the material used for the semiconductor intermediate layer is different. Its photoresponse test results are as follows: Figure 10 As shown.

[0133] Example 6

[0134] Following the method of Example 1, the carrier trapping layer material in step 5) was replaced with polyacrylonitrile instead of PVA, and the solvent was a 1:1 volume ratio of deionized water / ethanol mixed solvent. The structure of this device is the same as that obtained in Example 1, the only difference being the material used to prepare the carrier trapping layer.

[0135] Example 7

[0136] Following the method of Example 1, the carrier trapping layer material in step 5) was replaced with phenelzine C, and the carrier trapping layer was obtained using chemical vapor deposition. The structure of this device is the same as that obtained in Example 1, the only difference being the material and method used to prepare the carrier trapping layer.

[0137] In summary, the technical solution provided by this invention utilizes only organic transistors to change screen brightness. Specifically, when an external light source shines on the screen, the organic transistor changes the output power of its drain according to the brightness of the light source, thereby adjusting the screen brightness so that the screen dims rapidly in strong light and gradually brightens in weak light. Compared to existing technologies that require at least four circuits, the technical solution of this invention has a simple structure and does not require the cooperation of other functional circuits, thus having better adaptability.

[0138] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any changes or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in the present invention should be included within the scope of protection of the present invention.

Claims

1. A light-controlled active adaptive organic field-effect transistor, characterized in that, include: Semiconductor intermediate layer; The semiconductor intermediate layer includes: a photosensitive layer and a carrier trapping layer; The photosensitive layer is used to sense optical signals and generate photogenerated carriers; The carrier trapping layer is used to trap the photogenerated carriers; The semiconductor intermediate layer is used to adjust the decay time constant of the output current of the light-controlled adaptive organic field-effect transistor according to the brightness of the light signal.

2. The organic field-effect transistor according to claim 1, characterized in that, The carrier trapping layer is made of at least one of polyvinyl alcohol, polyacrylonitrile, and phenelzine C.

3. The organic field-effect transistor according to claim 1, characterized in that, The photosensitive layer is a bulk heterojunction, and the donor material of the bulk heterojunction includes: polythiophene system materials and pyrrolopyrrole dione materials, and the acceptor material of the bulk heterojunction includes: fullerene materials. The donor material is specifically one of PBTTT and its derivatives, P3HT and its derivatives, DPP-DTT and its derivatives, and PDPP3T and its derivatives. The receptor material is specifically PCBM and its derivatives.

4. The organic field-effect transistor according to claim 3, characterized in that, The photosensitive layer is made of PDPP3T and PCBM, with a mass ratio of PDPP3T to PCBM of 1:2 to 2:1; or, the photosensitive layer is made of P3HT and PCBM, with a mass ratio of P3HT to PCBM of 1:2 to 2:

1.

5. The organic field-effect transistor according to claim 1, characterized in that, The organic field-effect transistor further includes: an organic semiconductor layer; The organic semiconductor layer is a bulk heterojunction, and the donor material of the bulk heterojunction includes: polythiophene system materials and pyrrolopyrrole dione materials, and the acceptor material of the bulk heterojunction includes: fullerene materials. The donor material is specifically one of PBTTT and its derivatives, P3HT and its derivatives, DPP-DTT and its derivatives, and PDPP3T and its derivatives. The receptor material is specifically PCBM and its derivatives.

6. The organic field-effect transistor according to claim 5, characterized in that, The organic semiconductor layer is made of PDPP3T and PCBM, with a mass ratio of PDPP3T to PCBM of 1:2 to 2:1; or, the organic semiconductor layer is made of P3HT and PCBM, with a mass ratio of P3HT to PCBM of 1:2 to 2:

1.

7. The organic field-effect transistor according to claim 5, characterized in that, The thickness of the semiconductor intermediate layer is 10 nm to 100 nm; The thickness of the organic semiconductor layer is 10 nm to 100 nm.

8. The organic field-effect transistor according to any one of claims 1-7, characterized in that, The organic field-effect transistor further includes a substrate, a gate electrode, a lower insulating layer, an upper insulating layer, and a source electrode and a drain electrode located on the organic semiconductor layer. The substrate, gate electrode, lower insulating layer, semiconductor intermediate layer, upper insulating layer, and organic semiconductor layer are arranged sequentially from bottom to top.

9. A method for fabricating a light-controlled active adaptive organic field-effect transistor, characterized in that, For fabricating the organic field-effect transistor according to any one of claims 1-8, comprising: Step 1. Provide a substrate and fabricate a gate electrode on the substrate; Step 2. Prepare a lower insulating layer on the gate electrode; Step 3. Fabricate a semiconductor intermediate layer on the lower insulating layer; Step 4. Prepare an insulating layer on the semiconductor intermediate layer; Step 5. Prepare an organic semiconductor layer on the upper insulating layer; Step 6. Deposit source and drain electrodes on the organic semiconductor layer to obtain a light-controlled adaptive organic field-effect transistor.

10. The application of the light-controlled active adaptive organic field-effect transistor according to any one of claims 1-8 or the light-controlled active adaptive organic field-effect transistor prepared by the preparation method of claim 9 in simulating biological vision.

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