Synaptic transistor device with wide spectral response and method of fabrication thereof

Abstract

A synaptic transistor device with a wide spectral response is characterized by comprising: a floating gate layer for capturing light signals of different wavelengths to generate photogenerated carriers; a tunneling layer disposed on the floating gate layer for storing photogenerated carriers generated within the floating gate layer; an active layer disposed on the tunneling layer for transporting charge carriers and photogenerated carriers; source and drain electrodes, two source and drain electrodes symmetrically disposed on the active layer for providing a driving voltage to drive the flow of charge carriers and photogenerated carriers in the active layer, forming a circuit; a substrate disposed at the bottom of the synaptic transistor device for serving as the basis for fabricating the synaptic transistor device; a gate electrode disposed on the substrate for inducing charge carriers in the active layer; and an insulating layer disposed between the gate electrode and the floating gate layer for isolating the gate electrode and the active layer from conduction, wherein the floating gate layer is made of quantum dots with a wide spectral response, and a heterojunction structure is formed between the floating gate layer and the active layer.

Description

Technical Field

[0001] This invention relates to the field of transistor technology, and more specifically to a synaptic transistor device with a wide spectral response and its fabrication method. Background Technology

[0002] Over the past half-century, computers based on the von Neumann architecture have developed rapidly due to their advantages in solving structured mathematical problems. However, they are currently struggling to meet the growing demand for energy-efficient and intelligent computing because the frequent data transfers between the physically separated processor and memory in the von Neumann architecture consume enormous amounts of energy. As the most powerful information processor in nature, the brain is capable of high-speed computing with ultra-low power consumption and distributed parallel processing. The brain is also adept at intelligent activities such as self-learning, predicting future events, and language understanding. Therefore, brain-like computing is more energy-efficient and intelligent than von Neumann computing. As a result, neuromorphic computing that mimics brain functions is becoming one of the most important choices for next-generation computing.

[0003] Information transmission between neurons is achieved through synapses in the nervous system. The realization of neuromorphic computing largely depends on the development of synaptic devices. There are many synaptic devices based on changes in electrical stimulation resistance in the existing technology. However, due to the trade-off between bandwidth and connection density, these synaptic devices with changes in electrical stimulation resistance have disadvantages such as limited computing speed, susceptibility to interference, and high power consumption. In addition, existing photostimulated synaptic transistor devices are limited to responding to light stimulation in only one or two regions of ultraviolet, visible, or near-infrared light. Moreover, most photostimulated synaptic transistor devices have only explored responses to single-wavelength light signals and lack synaptic transistor devices that respond to a wide spectrum of ultraviolet, visible, and near-infrared light signals, which limits the further development of neuromorphic computing. Summary of the Invention

[0004] This invention is made to solve the above-mentioned problems, and its purpose is to provide a synaptic transistor device with a wide spectral response and a method for fabricating the same. To this end, the following technical solution is provided:

[0005] This invention provides a synaptic transistor device with a broad spectral response, characterized by comprising: a floating gate layer for capturing light signals of different wavelengths to generate photogenerated carriers; a tunneling layer disposed on the floating gate layer for storing photogenerated carriers generated within the floating gate layer; an active layer disposed on the tunneling layer for transporting charge carriers and photogenerated carriers; source / drain electrodes, two source / drain electrodes symmetrically disposed on the active layer for providing a driving voltage to drive the flow of charge carriers and photogenerated carriers in the active layer, forming a circuit; a substrate disposed at the bottom of the synaptic transistor device for serving as the basis for fabricating the synaptic transistor device; a gate electrode disposed on the substrate for inducing charge carriers in the active layer; and an insulating layer disposed between the gate electrode and the floating gate layer for isolating the gate electrode and the active layer from conduction. The floating gate layer is made of quantum dots with a broad spectral response, the active layer is made of an organic semiconductor material, and a heterojunction structure is formed between the floating gate layer and the active layer.

[0006] The synaptic transistor device with a wide spectral response provided by the present invention may also have the following feature: wherein the quantum dot material with a wide spectral response in the floating gate layer is at least one of lead sulfide quantum dots, lead selenide quantum dots, silver sulfide quantum dots, silver selenide quantum dots, copper indium selenide quantum dots, or mercury telluride quantum dots, and the light absorption range of the quantum dot material with a wide spectral response covers the ultraviolet, visible, and near-infrared regions.

[0007] The synaptic transistor device with a wide spectral response provided by the present invention may also have the following feature: wherein the tunneling layer is one of silicon dioxide, alumina, polymethyl methacrylate, polystyrene, polyvinyl alcohol, polyvinylpyrrolidone, or silk protein.

[0008] The synaptic transistor device with a wide spectral response provided by the present invention may also have the following feature: wherein the active layer material is an organic semiconductor with a benzene ring structure or a thiophene structure, and the thickness of the active layer is 5 nm to 100 nm.

[0009] The synaptic transistor device with a wide spectral response provided by the present invention may also have the following features: the source and drain electrode materials are one of doped silicon, conductive metal, conductive alloy or conductive metal oxide, and the thickness of the source and drain electrodes is 5 nm to 2000 nm.

[0010] The synaptic transistor device with a wide spectral response provided by the present invention may also have the following feature: wherein the substrate material is one of glass substrate, quartz substrate, silicon substrate, PET substrate or PEN substrate.

[0011] The synaptic transistor device with a wide spectrum response provided by the present invention may also have the following feature: wherein the gate electrode is one of doped silicon, conductive metal, conductive alloy or conductive metal oxide.

[0012] The synaptic transistor device with a wide spectral response provided by the present invention may also have the following feature: wherein the insulating layer material is one of silicon dioxide, aluminum oxide, polymethyl methacrylate, polystyrene, polyvinyl alcohol, polyvinylpyrrolidone, or silk protein.

[0013] This invention provides a method for fabricating a synaptic transistor device with a wide spectral response, characterized by the following steps: Step S1, setting a substrate; Step S2, fabricating a gate electrode on the substrate set in Step S1; Step S3, fabricating an insulating layer on the gate electrode fabricated in Step S2; Step S4, fabricating a floating gate layer on the insulating layer fabricated in Step S3 by spin coating, drop coating, lifting, printing, or other methods; Step S5, fabricating a tunneling layer on the floating gate layer fabricated in Step S4 by spin coating, drop coating, lifting, printing, or other methods; Step S6, fabricating an active layer on the tunneling layer fabricated in Step S5 by spin coating, vapor deposition, lifting, or printing; Step S7, fabricating two source / drain electrodes on the active layer fabricated in Step S6 by vapor deposition or imprinting.

[0014] The method for fabricating a synaptic transistor device with a wide spectral response provided by the present invention may also have the following features: wherein, in steps S4, S5 and S6, the process parameters of the spin coating method are a spin coating speed of 500 r / min-5000 r / min and a spin coating time of 10 s-200 s.

[0015] The role and effect of invention

[0016] According to the synaptic transistor device with a wide spectral response and its fabrication method, this invention introduces a quantum dot material with a wide spectral response into the floating gate layer of the synaptic transistor device to form a heterojunction structure with the active layer. This allows the floating gate layer to capture light signals of different wavelengths, thereby generating photogenerated carriers. The active layer can then transmit these photogenerated carriers under the action of the gate electrode and the source / drain electrode, enhancing the current originally caused by charge carriers in the synaptic transistor device. This achieves a wide spectral response of the synaptic transistor device, simulates the synaptic characteristics under a wide spectral range, broadens the application range and scenarios of photoresponsive synaptic transistor devices, and improves signal processing efficiency.

[0017] Therefore, compared with existing synaptic transistor devices based on electrical stimulation resistance changes and photostimulation synaptic transistor devices, the synaptic transistor device with wide spectral response provided by the present invention has the advantages of high bandwidth, strong anti-interference effect, low power consumption, high computing speed and high signal processing efficiency. It is not limited to responding to single wavelength signals, nor is it limited to responding to photostimulation in one or two regions of ultraviolet, visible or near-infrared light. Attached Figure Description

[0018] Figure 1 This is a structural diagram of a synaptic transistor device with a wide spectral response according to Embodiment 1 of the present invention;

[0019] Figure 2 This is a flowchart illustrating the fabrication of a synaptic transistor device with a broad spectral response according to the present invention;

[0020] Figure 3 These are the transistor transfer characteristic curves and output characteristic curves of the synaptic transistor device with a wide spectral response in Embodiment 1 of the present invention;

[0021] Figure 4 This is the ultraviolet-visible-near-infrared absorption spectrum of the floating gate layer, tunneling layer, and active layer of the synaptic transistor device with a wide spectral response in Embodiment 1 of the present invention.

[0022] Figure 5 This describes the excitatory postsynaptic current behavior of the synaptic transistor device with a wide spectral response in Embodiment 1 of the present invention under ultraviolet-visible-near-infrared light signals.

[0023] Figure 6 This describes the double-pulse facilitated behavior of the synaptic transistor device with a wide spectral response in Embodiment 1 of the present invention under ultraviolet-visible-near-infrared light signals;

[0024] Figure 7 This refers to the synaptic plasticity changes of the synaptic transistor device with a wide spectral response in Embodiment 1 of the present invention under ultraviolet-visible-near-infrared light signals;

[0025] Figure 8 This refers to the excitatory postsynaptic current behavior of the synaptic transistor device with a broad spectral response in Embodiment 2 of the present invention under ultraviolet-visible-near-infrared light signals; and

[0026] Figure 9 This describes the double-pulse facilitated behavior of the synaptic transistor device with a wide spectral response in Embodiment 2 of the present invention under ultraviolet-visible-near-infrared light signals. Specific implementation methods

[0027] To make the technical means, creative features, objectives and effects of the present invention easy to understand, the following embodiments, in conjunction with the accompanying drawings, specifically illustrate the synaptic transistor device with a wide spectral response and its preparation method.

[0028] <Example 1>

[0029] Figure 1 This is a structural diagram of a synaptic transistor device with a wide spectral response according to Embodiment 1 of the present invention.

[0030] like Figure 1 As shown, the synaptic transistor device 10 with a wide spectrum response provided in this embodiment includes a substrate 1, a floating gate layer 2, a tunneling layer 3, an active layer 4, a gate electrode 5, an insulating layer 6, and two source / drain electrodes 7.

[0031] The substrate 1 can serve as the basis for fabricating synaptic transistor devices. The material of the substrate 1 is preferably one of glass substrate, quartz substrate, silicon substrate, PET substrate or PEN substrate. In this embodiment, it is a silicon substrate.

[0032] The floating gate layer 2 can capture light signals of different wavelengths to generate photogenerated carriers. The material of the floating gate layer 2 is a quantum dot with a broad spectral response. The material is preferably at least one of lead sulfide quantum dots, lead selenide quantum dots, silver sulfide quantum dots, silver selenide quantum dots, copper indium selenide quantum dots, or mercury telluride quantum dots. In this embodiment, lead sulfide quantum dots are used.

[0033] The tunneling layer 3 can store photogenerated carriers generated within the floating gate layer. The material of the tunneling layer 3 is preferably one of silica, alumina, polymethyl methacrylate, polystyrene, polyvinyl alcohol, polyvinylpyrrolidone, or silk protein. In this embodiment, it is polymethyl methacrylate.

[0034] Depending on the manufacturing process, the floating gate layer 2 and the tunneling layer 3 can be fabricated as one layer at the same time, or they can be fabricated as two layers respectively. In this first embodiment, the floating gate layer 2 and the tunneling layer 3 are the same layer.

[0035] The active layer 4 is capable of transporting charge carriers and photogenerated carriers, and a heterojunction structure is formed between the floating gate layer 2 and the active layer 4. The material of the active layer 4 is an organic semiconductor with a benzene ring structure or a thiophene structure. The preferred material is an organic semiconductor with a benzene ring structure, including pentacene, C8-BTBT and DNTT, or an organic semiconductor with a thiophene structure, including P3HT, PQT-12, DPP-DTT, PDPP4T and PBTTT. In this embodiment, it is pentacene.

[0036] The gate electrode 5 can induce charge carriers in the active layer. The material of the gate electrode 5 is preferably one of doped silicon, conductive metal, conductive alloy or conductive metal oxide. In this embodiment, it is doped silicon.

[0037] Depending on the preparation process, the gate electrode 5 and the substrate 1 can be prepared as one layer at the same time, or they can be prepared as two layers respectively. In this first embodiment, the gate electrode 5 and the substrate 1 are the same layer, that is, this layer serves as both the gate electrode 5 and the substrate 1. The substrate 1 with the gate electrode 5 can be washed and dried before use.

[0038] The insulating layer 6 can isolate the conduction between the gate electrode and the active layer. The material of the insulating layer 6 is preferably one of silicon dioxide, alumina, polymethyl methacrylate, polystyrene, polyvinyl alcohol, polyvinylpyrrolidone or silk protein. In this embodiment, it is silicon dioxide.

[0039] The two source and drain electrodes 7 can provide a driving voltage, which can drive the flow of charge carriers and photogenerated carriers in the active layer to form a circuit. The material of the two source and drain electrodes 7 is preferably one of doped silicon, conductive metal, conductive alloy or conductive metal oxide. In this embodiment, it is a gold electrode.

[0040] Figure 2 This is a flowchart illustrating the fabrication of a synaptic transistor device with a broad spectral response according to the present invention;

[0041] like Figure 2 As shown, the method for fabricating a synaptic transistor device with a wide spectral response provided by the present invention includes the following steps:

[0042] Step S1, set the base;

[0043] Step S2: Fabricate a gate electrode on the substrate;

[0044] Step S3: An insulating layer is prepared on the gate electrode;

[0045] Step S4: The material used to prepare the floating gate layer is sequentially prepared on the insulating layer by spin coating, drop coating, dip coating and printing methods to obtain the floating gate layer;

[0046] Step S5: The material used to prepare the tunneling layer is sequentially prepared on the floating grid layer by spin coating, drop coating, dip coating and printing methods to obtain the tunneling layer;

[0047] Step S6: The material used to prepare the active layer is prepared on the tunneling layer by spin coating, vapor deposition, dip coating or printing to obtain the active layer;

[0048] Step S7: On the active layer, two source and drain electrodes are symmetrically prepared by vapor deposition or imprinting.

[0049] In steps S4, S5, and S6, the process parameters for the spin coating method are a spin coating speed of 500 r / min to 5000 r / min and a spin coating time of 10 s to 200 s.

[0050] In this first embodiment, a substrate 1 with a gate electrode 5 is used, and the floating gate layer 2 and the tunneling layer 3 are simultaneously fabricated into the same layer using a blending and spin-coating method. Therefore, the fabrication method of the synaptic transistor device with a broad spectral response in this first embodiment includes the following steps:

[0051] Corresponding to steps S1 and S2, a substrate 1 with a gate electrode 5 is provided;

[0052] In step S3, the substrate 1 with the gate electrode 5 is ultrasonically cleaned with acetone and isopropanol in sequence, then rinsed with deionized water and ethanol, and finally the surface of the substrate 1 with the gate electrode 5 is dried with a nitrogen gun and then dried. After that, silicon dioxide is deposited on the substrate 1 with the gate electrode 5 to obtain the insulating layer 6. In this first embodiment, the thickness of the insulating layer is 300 nm.

[0053] Corresponding to steps S4 and S5, a floating gate layer 2 and a tunneling layer 3 are prepared on the insulating layer 6 by a blending and spin-coating method. In this first embodiment, 1.5 mg / ml of lead sulfide quantum dots and 10 mg / ml of polymethyl methacrylate are dissolved in toluene solution by blending. The mixture is then spin-coated on the surface of the insulating layer 6 at a rotation speed of 3000 r / min and a spin-coating time of 60 s to sequentially form a blend film of the floating gate layer 2 and the tunneling layer 3.

[0054] Corresponding to step S6, on the floating gate layer 2 and tunneling layer 3, an organic semiconductor pentacene is deposited under high vacuum conditions using evaporation and deposition methods to obtain the active layer 4. The high vacuum condition is a vacuum level less than 1 × 10⁻⁶. -3 Pa, in this first embodiment, the thickness of the active layer 4 is 30 nm;

[0055] Corresponding to step S7, gold electrodes are deposited on the active layer 4 under high vacuum conditions using a masking method to fabricate two symmetrical source / drain electrodes 7, resulting in a synaptic transistor device with a broad spectral response. The high vacuum condition is defined as a vacuum level less than 1 × 10⁻⁶. -3 Pa, in this first embodiment, the thickness of a single source / drain electrode is 40 nm, the length of the conductive channel between the electrodes is 30 μm, and the width of the channel is 1 mm.

[0056] The synaptic transistor device with a wide spectrum response prepared by the preparation method of the synaptic transistor device with a wide spectrum response provided in this embodiment was subjected to performance testing. The transistor transfer characteristic curve and output characteristic curve were tested respectively. The synaptic characteristics under wide spectrum light signals (including simulating synaptic behaviors such as excitatory postsynaptic current and double-pulse facilitation under ultraviolet light, visible light and near-infrared light signals respectively) and the change of synaptic plasticity were tested. The test method is as follows: under room temperature and atmospheric environment, the corresponding tests are performed using a Keithley 4200 semiconductor tester and related probe station. The light source is a xenon lamp light source and an optical shutter to provide light signal pulses of specific wavelength and specific intensity.

[0057] First, a negative voltage is applied to the gate electrode 5 of the synaptic transistor device 10, and the same negative voltage is applied to the two source and drain electrodes 7 to drive the synaptic transistor device 10 to work, inducing charge carriers in the active layer and forming a circuit to generate current. When the synaptic transistor device 10 is illuminated, based on the heterojunction formed by the floating gate layer 2 and the active layer 4, photogenerated charge carriers are formed inside the floating gate layer 2. The photogenerated charge carriers include photogenerated electrons and photogenerated holes. At this time, a negative voltage is applied to the gate electrode 5, and the same negative voltage is applied to the two source and drain electrodes 7. Since the insulating layer 6 isolates the conduction between the gate electrode 5 and the active layer 4, due to the principle of parallel plate capacitor, the photogenerated holes will move to the active layer 4 to increase the original current of the synaptic transistor device, while the photogenerated electrons will remain in the floating gate layer 2. When the illumination is removed, due to the presence of the tunneling layer 3, the photogenerated electrons in the floating gate layer 2 will slowly attach with the photogenerated holes in the active layer 4, and the current will slowly decrease.

[0058] Figure 3 These are the transfer characteristic curves and output characteristic curves of the synaptic transistor device with a wide spectral response in Embodiment 1 of the present invention under dark and light conditions.

[0059] Figure 4 This is the ultraviolet-visible-near-infrared absorption spectrum of the floating gate layer, tunneling layer, and active layer of the synaptic transistor device with a wide spectral response in Embodiment 1 of the present invention.

[0060] like Figure 3 As shown, the synaptic transistor device prepared in Embodiment 1 of this invention has good transistor characteristics, such as... Figure 4 As shown, the synaptic transistor device prepared in Example 1 of this invention has an absorption range covering ultraviolet, visible, and near-infrared light. This test result is the basis for the synaptic transistor device to have a wide spectral response of ultraviolet-visible-near-infrared.

[0061] Figure 5 This describes the excitatory postsynaptic current behavior of the synaptic transistor device with a wide spectral response in Embodiment 1 of the present invention under ultraviolet-visible-near-infrared light signals.

[0062] Figure 6 This describes the double-pulse facilitated behavior of the synaptic transistor device with a wide spectral response in Embodiment 1 of the present invention under ultraviolet-visible-near-infrared light signals.

[0063] In this first embodiment, a simulation test of synaptic behavior was conducted. A 365nm wavelength light source was used as the ultraviolet light source, a 550nm wavelength light source as the visible light source, and an 850nm wavelength light source as the near-infrared light source. The same light pulse intensity and light pulse duration were used. Figure 5 and Figure 6 As shown, the synaptic transistor device prepared in Embodiment 1 of the present invention simulated excitatory postsynaptic current and double-pulse facilitated synaptic behavior under ultraviolet light, visible light and near-infrared light signals.

[0064] Figure 7 This refers to the synaptic plasticity changes of the synaptic transistor device with a wide spectral response in Embodiment 1 of the present invention under ultraviolet-visible-near-infrared light signals.

[0065] In this first embodiment, a test of changes in synaptic plasticity is performed, such as... Figure 7 As shown, by changing the pulse time of the optical signal, the synaptic transistor device prepared in Embodiment 1 of the present invention has achieved changes in synaptic plasticity under ultraviolet light, visible light and near-infrared light signals respectively. As the pulse time of the optical signal increases, the synaptic transistor device has achieved the transformation of synaptic plasticity from short-term plasticity to long-term plasticity under ultraviolet light, visible light and near-infrared light signals.

[0066] Functions and effects of Example 1

[0067] The synaptic transistor device with a broad spectral response according to the present invention achieves a response of the synaptic transistor device under ultraviolet-visible-near-infrared light signals by introducing a quantum dot material with a broad spectral response into the floating gate layer of the synaptic transistor and forming a heterojunction structure with the active layer, thus simulating the synaptic characteristics under a broad spectrum. Example 1 is based on... Figure 1 The device structure employs a heterojunction structure formed by quantum dot materials with a wide spectral response and an active layer, simulating synaptic characteristics under a wide spectral light signal. This includes simulating excitatory postsynaptic currents and double-pulse facilitation under ultraviolet, visible, and near-infrared light signals, respectively. Furthermore, it realizes the function of synaptic plasticity change under a wide spectral light signal. The device fabrication process is universal, broadening the application range and scenarios of photoresponsive synaptic transistor devices.

[0068] Therefore, compared with existing synaptic transistor devices based on electrical stimulation resistance changes and photostimulation synaptic transistor devices, the synaptic transistor device with wide spectral response provided by the present invention has the advantages of high bandwidth, strong anti-interference effect, low power consumption, high computing speed and high signal processing efficiency. It is not limited to responding to single wavelength signals, nor is it limited to responding to photostimulation in one or two regions of ultraviolet, visible or near-infrared light.

[0069] <Example 2>

[0070] For ease of explanation, the same symbols are used for structures identical to those in Embodiment 1, and the same descriptions are omitted in this embodiment.

[0071] In this second embodiment, the floating gate layer 2 is made of copper indium selenide quantum dots, the active layer 4 is made of organic semiconductor P3HT, and the other layers are made of the same materials as in the first embodiment.

[0072] In this second embodiment, a substrate 1 with a gate electrode 5 is used, and the floating gate layer 2 and the tunneling layer 3 are separately fabricated into two layers using a layered spin-coating method. Therefore, the fabrication method of the synaptic transistor device with a broad spectral response in this second embodiment includes the following steps:

[0073] Corresponding to steps S1 and S2, a substrate 1 with a gate electrode 5 is set;

[0074] In step S3, the substrate 1 with the gate electrode 5 is ultrasonically cleaned with acetone and isopropanol respectively, then rinsed with deionized water and ethanol, and finally the surface of the substrate 1 with the gate electrode 5 is dried with a nitrogen gun and then dried. After that, silicon dioxide is deposited on the substrate 1 with the gate electrode 2 to obtain the insulating layer 6. In this second embodiment, the thickness of the insulating layer is 300nm.

[0075] Corresponding to step S4, copper indium selenide quantum dots with a concentration of 10 mg / ml are spin-coated on the insulating layer 6 at a rotation speed of 3000 r / min and a spin-coating time of 60 s. After the solvent evaporates, a floating gate layer 2 is formed.

[0076] Corresponding to step S5, polymethyl methacrylate with a concentration of 10 mg / ml is spin-coated onto the floating grid layer 2 at a rotation speed of 3000 r / min and a spin-coating time of 60 s. After the solvent evaporates, a tunneling layer 3 is formed. In order to prevent the floating grid layer 2 from being damaged during spin-coating of the tunneling layer 3, the orthogonal solvent method is used in this second embodiment to solve this problem.

[0077] Corresponding to step S6, organic semiconductor P3HT with a concentration of 5 mg / ml is spin-coated onto the tunneling layer 3 at a rotation speed of 2000 r / min and a spin-coating time of 40 s, and then annealed at an annealing temperature of 60°C and an annealing time of 30 min to form an active layer 4. In order to prevent the tunneling layer 3 from being damaged during spin-coating of the active layer 4, the orthogonal solvent method is used in this second embodiment to solve this problem.

[0078] Corresponding to step S7, gold electrodes are deposited on the active layer 4 under high vacuum conditions using evaporation and masking to fabricate two symmetrical source / drain electrodes 7, resulting in a synaptic transistor device with a broad spectral response. The high vacuum condition is defined as a vacuum level less than 1 × 10⁻⁶. -3 Pa, in this second embodiment, the thickness of a single source / drain electrode 7 is 40 nm, the length of the conductive channel between the electrodes is 30 μm, and the width of the channel is 1 mm.

[0079] Figure 8 This describes the excitatory postsynaptic current behavior of the synaptic transistor device with a wide spectral response in Embodiment 2 of the present invention under ultraviolet-visible-near-infrared light signals.

[0080] Figure 9 This describes the double-pulse facilitated behavior of the synaptic transistor device with a wide spectral response in Embodiment 2 of the present invention under ultraviolet-visible-near-infrared light signals.

[0081] The performance of the synaptic transistor device with a wide spectral response prepared by the method of Example 2 was tested. A 365nm wavelength light source was used as the ultraviolet light source, a 500nm wavelength light source as the visible light source, and an 850nm wavelength light source as the near-infrared light source. The remaining test methods in Example 2 were the same as those in Example 1, using the same light pulse intensity and duration to simulate synaptic behavior. Figure 8 and Figure 9 As shown, the synaptic transistor device prepared in Embodiment 2 of the present invention also simulated the excitatory postsynaptic current and double-pulse facilitated synaptic behavior under ultraviolet light, visible light and near-infrared light signals, respectively.

[0082] Functions and effects of Example 2

[0083] In this second embodiment, materials different from those in the first embodiment were used. The floating gate layer 2 was made of copper indium selenide quantum dots, and the active layer 4 was made of organic semiconductor P3HT. The floating gate layer 2 and the tunneling layer 3 were separately prepared into two layers using a spin-coating method. The synaptic transistor device prepared by the method in the second embodiment also simulated the excitatory postsynaptic current and double-pulse facilitated synaptic behavior under ultraviolet light, visible light and near-infrared light signals.

[0084] Therefore, compared with existing synaptic transistor devices based on electrical stimulation resistance changes and photostimulation synaptic transistor devices, the synaptic transistor device with wide spectral response provided by the present invention has the advantages of high bandwidth, strong anti-interference effect, low power consumption, high computing speed and high signal processing efficiency. It is not limited to responding to single wavelength signals, nor is it limited to responding to photostimulation in one or two regions of ultraviolet, visible or near-infrared light.

[0085] The above-described implementation method is a preferred embodiment of the present invention and is not intended to limit the scope of protection of the present invention.

Claims

1. A synaptic transistor device with a broad spectral response, characterized in that, include: Floating gate layers are used to capture light signals of different wavelengths to generate photogenerated carriers. A tunneling layer, disposed on the floating gate layer, is used to store the photogenerated carriers generated within the floating gate layer; An active layer, disposed on the tunneling layer, is used to transport charge carriers and photogenerated carriers; Source and drain electrodes, two of which are symmetrically disposed on the active layer, are used to provide a driving voltage to drive the flow of charge carriers and photogenerated carriers in the active layer to form a circuit; A substrate is disposed at the bottom of the synaptic transistor device and serves as the basis for fabricating the synaptic transistor device. A gate electrode, disposed on the substrate, is used to induce the charge carriers in the active layer; An insulating layer is disposed between the gate electrode and the floating gate layer to isolate the conduction between the gate electrode and the active layer. The floating gate layer is made of quantum dots with a wide spectral response, the active layer is made of organic semiconductor material, and a heterojunction structure is formed between the floating gate layer and the active layer.

2. The synaptic transistor device with a wide spectral response according to claim 1, characterized in that: in, The quantum dot material with a broad spectral response in the floating grating layer is at least one of lead sulfide quantum dots, lead selenide quantum dots, silver sulfide quantum dots, silver selenide quantum dots, copper indium selenide quantum dots, or mercury telluride quantum dots. The quantum dot material with a broad spectral response covers the absorption range of ultraviolet, visible, and near-infrared light regions.

3. The synaptic transistor device with a wide spectral response according to claim 1, characterized in that: in, The tunneling layer is one of silica, alumina, polymethyl methacrylate, polystyrene, polyvinyl alcohol, polyvinylpyrrolidone, or silk protein.

4. The synaptic transistor device with a wide spectral response according to claim 1, characterized in that: in, The active layer material is an organic semiconductor with a benzene ring structure or a thiophene structure, and the thickness of the active layer is 5 nm to 100 nm.

5. The synaptic transistor device with a wide spectral response according to claim 1, characterized in that: in, The source and drain electrode material is one of doped silicon, conductive metal, conductive alloy or conductive metal oxide, and the thickness of the source and drain electrode is 5nm to 2000nm.

6. The synaptic transistor device with a wide spectral response according to claim 1, characterized in that: in, The substrate material is one of glass substrate, quartz substrate, silicon substrate, PET substrate or PEN substrate.

7. The synaptic transistor device with a wide spectral response according to claim 1, characterized in that: in, The gate electrode is one of doped silicon, conductive metal, conductive alloy, or conductive metal oxide.

8. The synaptic transistor device with a wide spectral response according to claim 1, characterized in that: in, The insulating layer material is one of silicon dioxide, aluminum oxide, polymethyl methacrylate, polystyrene, polyvinyl alcohol, polyvinylpyrrolidone, or silk protein.

9. A method for fabricating a synaptic transistor device with a broad spectral response, used to fabricate the synaptic transistor device with a broad spectral response as described in any one of claims 1-8, characterized in that, Includes the following steps: Step S1, setting the substrate; Step S2: The gate electrode is fabricated on the substrate; Step S3: Prepare the insulating layer on the gate electrode; Step S4: The material used to prepare the floating gate layer is sequentially prepared on the insulating layer by spin coating, drop coating, lifting and printing methods to obtain the floating gate layer; Step S5: The material used to prepare the tunneling layer is sequentially prepared on the floating grid layer by spin coating, drop coating, dip coating and printing methods to obtain the tunneling layer; Step S6: The material used to prepare the active layer is prepared on the tunneling layer by spin coating, vapor deposition, dip coating or printing to obtain the active layer; Step S7: On the active layer, two source and drain electrodes are prepared by vapor deposition or imprinting.

10. The method for fabricating a synaptic transistor device with a broad spectral response according to claim 9, characterized in that: in, In steps S4, S5, and S6, the process parameters of the spin coating method are a spin coating speed of 500 r / min to 5000 r / min and a spin coating time of 10 s to 200 s.

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