Dynamic reconfigurable organic photosensitive field effect transistor and manufacturing method thereof

Abstract

The invention belongs to the technical field of semiconductor industry storage technology and organic electronics and information, and particularly relates to a dynamic reconfigurable organic photosensitive field effect transistor and a manufacturing method thereof. The dynamic reconfigurable organic photosensitive field effect transistor comprises a gate electrode, a gate insulating layer, an electrolyte layer, an organic photosensitive charge trapping layer, an organic photosensitive semiconductor layer and source and drain electrodes from bottom to top. The organic photosensitive field effect transistor is based on a double-photosensitive-layer structure, an electrolyte layer is additionally introduced, and the dynamic reconfiguration of light current is successfully realized by utilizing a photon-electron-ion multi-mechanism coupling effect; by changing the grid voltage and the source-drain voltage, the volatility-to-non-volatility reconfigurability of the light current is realized; according to the organic photosensitive field effect transistor, the spectral range of a device can be expanded through a double-photosensitive-layer structure, and sensing from ultraviolet light to visible light is achieved. In addition, the organic photosensitive field effect transistor utilizes a negative photoconductive effect to sense light information in a weaker light environment.

Description

Technical Field

[0001] The present invention belongs to the fields of semiconductor industry storage technology, organic electronics and information technology, and in particular relates to a dynamically reconfigurable organic photosensitive field-effect transistor and a manufacturing method thereof. Background Art

[0002] Artificial vision systems, a crucial component of intelligent edge computing, have long been limited by traditional complementary metal-oxide-semiconductor (CMOS) technology and the von Neumann architecture. In these systems, image processing efficiency is significantly impacted by the independent and physically separate image sensors, storage modules, and processors. This separation leads to significant data redundancy and signal processing delays, increasing circuit complexity and power consumption, which in turn limits real-time processing capabilities. In natural environments, traditional vision systems must sequentially complete a complex series of steps, including signal capture and image processing, resulting in low efficiency.

[0003] Previous research has typically employed two approaches: first, replacing artificial synaptic devices with idealized software simulation models to perform weight storage and update functions within artificial neural networks; and second, leveraging sensors to convert different types of information into a single type of electrical signal for subsequent processing. Furthermore, in most studies, information processing relies on additional edge computing devices. These factors have fundamentally limited the future application potential of artificial vision systems. In recent years, in-sensor computing, a novel architecture that integrates perception and computing, has gained widespread attention due to its in-memory computing and neuromorphic properties. In this field, the integration of optical neural networks with brain-inspired neural networks has opened up new developments in machine vision, enabling real-time, low-power processing of complex spatiotemporal images. However, current neuromorphic visual perception devices have numerous limitations. Their relatively simple dynamic characteristics preclude simultaneous spatiotemporal information encoding and pulse encoding, and their relatively limited operating modes limit their practical application.

[0004] Organic photosensitive field-effect transistors use organic photosensitive materials as their core functional layer and operate based on a charge capture / release mechanism. They have the advantages of fast signal transmission speed, large response bandwidth, and low power consumption, and have broad application prospects in the field of electronic information. For example, patent document CN118234262A discloses a preparation method and application of an organic photosensitive field-effect transistor with a negative photoconductivity effect. However, the organic photosensitive field-effect transistors in the existing technology have not yet achieved an adjustable multi-time-scale photoelectric response.

[0005] Electrolyte-gated transistors have adjustable ion dynamics timescales under different gate voltage conditions, demonstrating great potential for achieving multifunctionality in a single device for dynamic information processing. Combining these two devices with different operating mechanisms, through the multi-mechanism coupling of "photon-electron-ion," is expected to achieve adjustable multi-timescale photoelectric responses. This, in turn, enables spatiotemporal information encoding and pulse signal processing, laying a key foundation for building large-scale, reconfigurable visual computing hardware systems. However, existing technologies do not provide examples of such a combination. Summary of the Invention

[0006] Based on the above background, the purpose of the present invention is to develop a dynamically reconfigurable organic photosensitive field-effect transistor with stable structure and excellent performance. The present invention designs a dynamically reconfigurable organic photosensitive field-effect transistor, which introduces an organic photosensitive charge trapping layer under the organic photosensitive semiconductor layer to form a double photosensitive layer structure, and realizes the reduction of channel current under light illumination through the grating effect. An electrolyte layer is introduced under the double photosensitive layer structure, and the volatility / non-volatility dynamic reconfiguration of the photocurrent is realized through the dynamic competition between the double electric layer effect and the grating effect. The present invention enhances the weak light detection capability of the device through "photon-electron-ion" coupling, expands the spectral perception range of the device, and realizes the reconfiguration of the storage mode and response polarity of the photocurrent, which is expected to be used to build a visual computing hardware system with reconfigurability and compatibility with multiple types of algorithms.

[0007] To achieve the above results, the technical solution adopted by the present invention is:

[0008] In a first aspect, the present invention provides a dynamically reconfigurable organic photosensitive field effect transistor, such as Figure 1 The figure shows a schematic structural diagram of a dynamically reconfigurable organic photosensitive field effect transistor, which comprises, from bottom to top, a gate 1, a gate insulating layer 2, an electrolyte layer 3, an organic photosensitive charge trapping layer 4, an organic photosensitive semiconductor layer 5, and source-drain electrodes, i.e., a source electrode 6 and a drain electrode 7. The organic photosensitive charge trapping layer is made of an organic photosensitive electret material with a strong charge storage capacity. It should be noted that the strong charge storage capacity mentioned in the present invention refers to a charge storage density of the organic photosensitive electret material exceeding 4×10 12 C / m 2 , which is used to achieve large-capacity capture of photogenerated charges under illumination, and the charge storage density (Δn) is defined as the number of charge carriers captured per unit area, Δn=(ΔV th ·C i ) / e, where ΔV th is the charge storage window, C i is the total capacitance per unit area, e is the unit charge 1.602×10 -19C. The electrolyte layer is prepared from a polyelectrolyte material. The polyelectrolyte material of the present invention refers to a natural water-soluble polymer material, the structural units of which contain ionizable groups and have good ionic conductivity.

[0009] Preferably, the polyelectrolyte layer is prepared from one or more materials selected from chitosan (CAS: 9012-76-4), sodium alginate (CAS: 9005-38-3), and polyquaternium-11 (53633-54-8).

[0010] Preferably, the thickness of the polyelectrolyte layer is 300 to 500 nm.

[0011] Preferably, the preparation material of the organic photosensitive electret layer is selected from one or more of [6,6]-phenyl-C61-butyric acid isomethyl ester (PCBM) (CAS: 160848-22-6), poly [2-methoxy-5-(2-ethylhexyloxy)-1,4-phenylethynyl] (MEH-PPV) (CAS: 138184-36-8), poly (N-vinylcarbazole) (PVK) (CAS: 25067-59-8), poly (9,9-dioctylfluorene-co-benzothiadiazole) (F8BT) (CAS: 210347-52-7), and poly (9,9-dioctylfluorene-2,7-diyl) (PFO) (CAS: 123864-00-6). For example, the charge storage density of PCBM is 4.2846×10 12 C / m 2 , indicating that it has strong charge storage capacity.

[0012] Preferably, the thickness of the organic photosensitive electret layer is 10-50 nm.

[0013] Preferably, the material for preparing the organic photosensitive semiconductor layer is selected from one or more of pentacene (CAS: 135-48-8), poly (3-hexylthiophene-2,5-diyl) (P3HT) (CAS: 156074-98-5), 2,7-dioctyl [1] benzothieno [3,2-b] benzothiophene (C8-BTBT) (CAS: 583050-70-8) or dinaphtho [2,3-B: 2′, 3′-F] thieno [3,2-B] thiophene (DNTT) (CAS: 935280-42-5).

[0014] Preferably, the thickness of the organic semiconductor layer is 40 to 60 nm.

[0015] Preferably, the absorption spectrum of the organic photosensitive electret and the absorption spectrum of the organic photosensitive semiconductor complement each other. The complementary absorption spectra described in the present invention refer to the fact that the wavelength ranges with the strongest absorption intensity of the two do not overlap. Compared to a single functional layer, the present invention selects photosensitive materials with complementary absorption spectral ranges to design an organic photosensitive field-effect transistor with a dual photosensitive layer, which can significantly broaden the device's absorption spectrum range and achieve a wide-wavelength light response. Furthermore, as a preferred embodiment of the dynamically reconfigurable organic photosensitive field-effect transistor of the present invention, the organic photosensitive charge-trapping layer is made of the organic photosensitive electret F8BT, and the organic photosensitive semiconductor layer is made of pentacene. Because a single-layer film made solely of pentacene has very weak absorption in the 400nm to 550nm range, and a single-layer film made solely of F8BT has very weak absorption in the 550nm to 700nm range, forming a dual photosensitive layer by forming a layer of pentacene on the F8BT film significantly improves the absorption intensity of the dual photosensitive layer in both of the aforementioned wavelength ranges.

[0016] Preferably, the gate electrode is made of a material selected from the group consisting of highly doped silicon, Cu, Au, Ag, and Pt. The highly doped silicon refers to a silicon wafer with oxide doped on its surface.

[0017] Preferably, the gate insulating layer is made of any one of hafnium oxide, titanium oxide, zirconium oxide, silicon dioxide or aluminum oxide, and has a film thickness of 10 to 300 nm.

[0018] Preferably, the source-drain electrodes are grown on both sides of the conductive channel, and their preparation material is one of Cu, Au or Pt, their thickness is 80 to 110 nm, and their preparation method is magnetron sputtering or vacuum evaporation; further preferably, the source-drain electrode material is copper.

[0019] Preferably, the length of the conductive channel between the source and the drain is 50-200 μm, and the width of the conductive channel between the source and the drain is 1000-2000 μm.

[0020] In a second aspect, the present invention provides a preferred method for preparing the dynamically reconfigurable organic photosensitive field-effect transistor according to the first aspect, comprising the following steps:

[0021] Step S1, dissolving the natural water-soluble polymer material in deionized water to prepare a solution with a concentration of 10 to 40 mg / mL, shaking and stirring in a cleaning machine for 2 to 3 hours, and then standing for 8 to 12 hours;

[0022] Step S2, dissolving the organic photosensitive electret material with strong charge storage capacity in an organic solvent to prepare a solution with a concentration of 3 to 10 mg / mL, adding polytetrafluoroethylene magnets, heating and stirring on a heating platform for 2 to 3 hours, and then standing for 8 to 12 hours;

[0023] Step S3, selecting highly doped silicon as the gate electrode and silicon dioxide as the gate insulating layer, with the thickness of the gate insulating layer being 50 to 300 nm;

[0024] Step S4, ultrasonically cleaning the surface of the silicon wafer in step S3 using acetone, ethanol, and deionized water, respectively, for 5 to 10 minutes, and drying at 120° C. after cleaning;

[0025] Step S5, treating the dried clean silicon wafer with ultraviolet ozone for 5 to 10 minutes;

[0026] Step S6, forming an organic photosensitive electret film with a thickness of 10 to 50 nm using the organic photosensitive electret solution prepared in step S1 on the cleaned silicon wafer in step S5 by one or more methods selected from the group consisting of solution processing, vacuum evaporation, molecular beam epitaxy, sputtering, laser pulse deposition, and inkjet printing, and annealing the film in vacuum at 80° C. for 30 minutes;

[0027] Step S7 , on the sample annealed in step S6 , an organic photosensitive semiconductor layer and a source-drain electrode are sequentially prepared by vacuum evaporation coating.

[0028] Preferably, the organic solvent in step S2 is any one of tetrahydrofuran, 1'2-dichloroethane, chlorobenzene or toluene.

[0029] Preferably, the solution processing method in step S6 is spin coating, and the spin coating speed is set to 3000 r / min and the time is 40 s.

[0030] Preferably, the organic photosensitive semiconductor material is pentacene, and the vacuum evaporation deposition rate of the organic photosensitive semiconductor layer in step S7 is The vacuum degree is controlled at 5×10 -4 pa~5×10 -5 pa, and use crystal oscillator to control the thickness between 40 and 60 nm;

[0031] Preferably, the source and drain electrodes are made of copper, and the evaporation rate of the vacuum evaporation coating of the source and drain electrodes in step S7 is The thickness of the source and drain electrodes is controlled within a range of 80 to 110 nm.

[0032] The above-mentioned dynamically reconfigurable organic photosensitive field-effect transistor provided by the present invention successfully realizes the dynamic reconfiguration of the volatility / non-volatility of the channel current under light by introducing an electrolyte layer under the double photosensitive layer structure. The volatility / non-volatility of the channel photocurrent of the organic photosensitive field-effect transistor and the response polarity of the photocurrent can be regulated by using the source-drain voltage and the gate voltage.

[0033] Beneficial effects:

[0034] (1) The organic photosensitive field-effect transistor prepared by the present invention exhibits positive / negative photoconductivity effects, which are rarely reported in this field. Within the absorption spectrum, the positive / negative response polarity of the photocurrent can be changed by changing the drain voltage. Furthermore, the device can achieve photoresponse under very weak illumination, and the response speed is very fast. It has broad application prospects in photodetection, photoelectric storage, and other aspects, and is an important foundation for the development of multifunctional integrated optoelectronic devices.

[0035] (2) The organic photosensitive field effect transistor prepared by the present invention innovatively adopts a dual photosensitive layer structure. Compared with a single photosensitive layer, the dual photosensitive layer structure can fully utilize the photosensitive characteristics of the storage layer, improve the conversion efficiency of photogenerated charges, and increase the number of photogenerated charges to be captured. When a large voltage is applied to the gate, the mobile holes in the photosensitive semiconductor are captured by the semiconductor layer / organic electret layer interface and the organic electret body under the action of the gate voltage, thereby achieving effective regulation of the current suppression of the organic photosensitive field effect transistor under light signals. In addition, the organic photosensitive field effect transistor can expand the spectral range of the device through the dual photosensitive layer structure, realizing the perception of ultraviolet to visible light, that is, the wavelength range of 300 to 700 nm.

[0036] (3) The organic photosensitive field-effect transistor provided by the present invention introduces an electrolyte layer on the basis of a double-photosensitive layer structure, and realizes the volatility / non-volatility control of the channel photocurrent by modulating the source-drain voltage and the gate voltage and utilizing the competitive relationship between the double-layer effect and the grating effect. This strategy solves the limitation of the single working mode of the photosensitive field-effect transistor and significantly improves the light perception and encoding capabilities as well as the nonlinear computing capabilities. In general, this new device provides strong support for the construction of visual computing systems with higher adaptability and efficiency, and has broad application prospects.

[0037] (4) The present invention adopts a simple spin coating process to prepare the organic photosensitive charge capture layer and the electrolyte layer. The preparation process is simple, which greatly reduces the preparation cost of the device and has great commercial value. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] The present invention will be further described below with reference to the accompanying drawings.

[0039] Figure 1The device structure of the dynamically reconfigurable organic photosensitive field-effect transistor according to the present invention;

[0040] Figure 2 is the ultraviolet-visible light absorption curve of the charge trapping layer, the organic photosensitive semiconductor layer and the electrolyte layer in the organic photosensitive field effect transistor prepared in Example 1;

[0041] Figure 3 This is the "8" hysteresis curve of the dynamic reconfigurable organic photosensitive field effect transistor tested with F8BT as the organic photosensitive electret layer and chitosan as the electrolyte layer according to the present invention;

[0042] Figure 4 The transfer curves of the dynamically reconfigurable organic photosensitive field-effect transistor using F8BT as the organic photosensitive electret layer and chitosan as the electrolyte layer under different light wavelengths are shown in the present invention.

[0043] Figure 5 Output curves of the dynamically reconfigurable organic photosensitive field-effect transistor using F8BT as the organic photosensitive electret layer and chitosan as the electrolyte layer under dark and light conditions;

[0044] Figure 6 This is a postsynaptic current curve test of the dynamically reconfigurable organic photosensitive field-effect transistor using F8BT as the organic photosensitive electret layer and chitosan as the electrolyte layer as described in the present invention;

[0045] Figure 7 The hysteresis curves of the dynamically reconfigurable organic photosensitive field-effect transistor using F8BT as the organic photosensitive electret layer and sodium alginate as the electrolyte layer under dark and light conditions are shown in the figure.

[0046] Figure 8 The postsynaptic current curve test under different reading voltages of the dynamically reconfigurable organic photosensitive field-effect transistor using F8BT as the organic photosensitive electret layer and sodium alginate as the electrolyte layer according to the present invention;

[0047] Figure 9 The postsynaptic current curve test under different source-drain voltages of the dynamically reconfigurable organic photosensitive field-effect transistor using F8BT as the organic photosensitive electret layer and sodium alginate as the electrolyte layer according to the present invention; DETAILED DESCRIPTION

[0048] The present invention is further described below by means of specific examples. However, it should be noted that these embodiments are not intended to limit the present invention, and any functional, methodological, or structural equivalents or replacements made by persons of ordinary skill in the art based on these embodiments are all within the scope of protection of the present invention.

[0049] In the following embodiments, the gate and gate insulating layer are finished products purchased from Suzhou Jingsi Electronic Technology Co., Ltd., with a surface of 90nm silicon dioxide as the gate insulating layer and a bottom layer of silicon as the gate, with an area of 1.5×1.5cm 2 .

[0050] In the following examples, chitosan was purchased from Sigma-Aldrich, product number: C3646-10G.

[0051] In the following examples, a Keithley 2636B semiconductor parameter analyzer was used to perform performance tests on the prepared organic photosensitive field effect transistors.

[0052] In the following embodiments, an adjustable monochromatic light source from Beijing Newbit Corporation and a GCI-73M precision electronic timer from Daheng New Era Technology Co., Ltd. were used to apply light pulses to the prepared organic photosensitive field effect transistor.

[0053] Example 1:

[0054] This embodiment 1 is a preparation process of a dynamically reconfigurable organic photosensitive field-effect transistor using F8BT as an organic photosensitive electret layer and chitosan as an electrolyte layer.

[0055] In the technical solution of this embodiment, the electrolyte layer is made of chitosan, with a thickness of 300nm. The organic photosensitive charge-trapping layer is made of the photosensitive polymer poly(9,9-dioctylfluorene-co-benzothiadiazole) (F8BT), with a thickness of 20nm. N-type heavily doped silicon serves as the substrate and gate electrode. The gate insulating layer is made of silicon dioxide, with a thickness of 90nm. A 180nm thick layer of chitosan in deionized water is spin-coated on the gate insulating layer as the electrolyte layer. A 20nm thick layer of F8BT in chlorobenzene is spin-coated on the electrolyte layer as the organic photosensitive charge-trapping layer. A 50nm thick layer of pentacene is evaporated on the organic photosensitive charge-trapping layer as the organic photosensitive semiconductor layer. Cu is then evaporated on both sides of the conductive channel as the source and drain electrodes. In this example, choosing Cu as the source and drain electrode material rather than Au can reduce the device's manufacturing cost. The concentration of chitosan in deionized water was 30 mg / mL. The electrolyte layer was formed by spin coating, with the speed of the benchtop coater set at 6000 rpm for 60 s. The concentration of F8BT in chlorobenzene solution was 5 mg / mL. The organic photosensitive charge trapping layer was formed by spin coating, with the speed of the benchtop coater set at 3000 rpm for 40 s. The organic semiconductor layer, pentacene, was formed by thermal vacuum evaporation at a rate of The vacuum degree is controlled at 5×10 -4 pa~5×10-5 pa, the thickness is controlled by crystal oscillator at 40-60nm; the preparation method of source and drain electrode copper is thermal vacuum evaporation method, and the evaporation rate is The vacuum degree is controlled at 5×10 -4 pa~5×10 -5 The thickness of the pa is controlled by a crystal oscillator at 80 to 110 nm. During device preparation, the laboratory room temperature needs to be maintained at around 25°C and the indoor humidity needs to be kept below 40%.

[0056] Figure 2 These are the UV-visible absorption curves of the organic photosensitive charge-trapping layer, organic photosensitive semiconductor layer, and organic photosensitive charge-trapping layer / organic photosensitive semiconductor layer of the dynamically reconfigurable organic photosensitive field-effect transistor prepared in Example 1, using F8BT as the organic photosensitive electret layer and chitosan as the electrolyte layer. The specific testing process involved ultrasonically cleaning three 1.5×1.5 cm quartz wafers with acetone, ethanol, and deionized water for 10 minutes, respectively. After cleaning, the wafers were dried at 120°C. The dried wafers were then treated with UV-ozone for 5–10 minutes. After UV-ozone treatment, two of the wafers were spin-coated with a 6 mg / ml solution of F8BT in chlorobenzene as the organic photosensitive charge-trapping layer. A layer of pentacene as the organic photosensitive semiconductor layer was then vacuum-deposited on one of the wafers and the uncoated wafer. Spectral measurements of the three wafers were then performed using a LAMBDA 650S UV-Vis spectrophotometer. The results show that the device has a wide spectral absorption range of 300-700nm, which can effectively perceive external ambient light from ultraviolet to visible light.

[0057] Figure 3 This is the hysteresis curve for the dynamically reconfigurable organic photosensitive field-effect transistor prepared in Example 1, using F8BT as the organic photosensitive electret layer and chitosan as the electrolyte layer. At a source-drain voltage of -10V, i.e., the saturated drain voltage, a figure-of-eight hysteresis phenomenon occurs. In the low gate voltage region, the reverse current exceeds the forward current, indicating a dominant double-layer effect. When the gate voltage continues to sweep in the negative gate voltage direction, i.e., as the gate voltage continues to increase, the forward current exceeds the reverse current, indicating that the characteristic curve in this region is primarily driven by the charge trapping effect.

[0058] Figure 4 The transfer characteristic curves of the dynamically reconfigurable organic photosensitive field effect transistor prepared in Example 1 with F8BT as the organic photosensitive electret layer and chitosan as the electrolyte layer at different wavelengths were tested. When the source-drain voltage was fixed at -10V and the light intensity was fixed at 3mW / cm 2, respectively, using 345nm, 470nm, 500nm, and 670nm wavelength light irradiation. From the transfer curves, it can be seen that the device has a good field effect, and under the conditions of different wavelengths of light, the source-drain current is significantly reduced compared to the dark condition, showing a typical negative photoconductivity effect.

[0059] Figure 5 The output curve of the dynamically reconfigurable organic photosensitive field effect transistor prepared in Example 1 with F8BT as the organic photosensitive electret layer and chitosan as the electrolyte layer is tested. When the gate voltage is fixed at 0V, -2V, -4V, -6V, -8V and -10V, the output curves under light and darkness are obtained. The light intensity is 3mW / cm 2 The output curve shows that the device has a good field effect, and under light conditions, the source-drain current is significantly reduced compared to that under dark conditions, showing a typical negative photoconductivity effect.

[0060] Figure 6 This is the postsynaptic current curve test of the dynamically reconfigurable organic photosensitive field effect transistor prepared in Example 1 with F8BT as the organic photosensitive electret layer and chitosan as the electrolyte. Figure a shows the test result with a reading voltage of -5V, and Figure b shows the test result with a reading voltage of -10V. When the source-drain voltage is fixed at -10V and the light intensity is 3mW / cm 2 The device was irradiated with white light five times, with a light pulse time of 100ms and a pulse interval of 100ms. It can be seen from the postsynaptic current curve that under light conditions, the channel current is significantly reduced compared to that under dark conditions, showing a negative photoconductivity phenomenon. Under different reading voltages, the current after stimulation shows different volatilities. When the reading voltage is -5V, the current after stimulation quickly returns to the initial state, showing obvious volatility; when the reading voltage is -10V, the current after stimulation does not return to the initial state, but maintains a current level lower than the initial state, showing obvious non-volatility. This shows that the device structure design strategy proposed in this application can well realize dynamic reconfiguration. This strategy solves the limitation of the single working mode of the photosensitive field-effect transistor.

[0061] Example 2: Preparation process of a dynamically reconfigurable organic photosensitive field-effect transistor using F8BT as an organic photosensitive electret layer and sodium alginate as an electrolyte layer

[0062] The structure of the dynamically reconfigurable organic photosensitive field-effect transistor provided in this embodiment is substantially the same as that of Example 1, with the only difference being that the electrolyte layer 3 is made of sodium alginate and has a thickness of 300 to 500 nm. The device fabrication process in this embodiment is the same as that in Example 1.

[0063] Figure 7 It is the hysteresis curve of the dynamically reconfigurable organic photosensitive field effect transistor prepared in Example 2 with F8BT as the organic photosensitive electret layer and sodium alginate as the electrolyte layer under light conditions and dark conditions, and is irradiated with blue light with a wavelength of 470nm. Under dark conditions, the phenomenon of the hysteresis curve is similar to that of Example 1. When the source-drain voltage is -10V, that is, the saturated drain voltage, an "8"-shaped hysteresis phenomenon occurs. In the low gate voltage region, the reverse current is higher than the forward current, showing that the double layer effect is dominant; in the high gate voltage region, the forward current is higher than the reverse current, and the characteristic curve in this region is mainly determined by the charge trapping effect. Under light conditions, the hysteresis window is significantly increased, and the saturation current is lower than the saturation current under dark conditions, showing a typical negative photoconductivity effect dominated by photogenerated holes.

[0064] Figure 8 The postsynaptic current curves of the dynamically reconfigurable organic photosensitive field-effect transistor prepared in Example 2 with F8BT as the organic photosensitive electret layer and sodium alginate as the electrolyte layer based on different reading voltages are obtained with a wavelength of 470 nm and a light intensity of 1 mW / cm 2 As can be seen from the figure, when the source-drain voltage is fixed at -1V and the reading voltage is -1V, -3V, and -5V, the intensity applied to the device is 1mW / cm 2 The device's current level was significantly excited by a 1s light pulse, and the non-volatility of the stimulated current increased with the increase of the read voltage, indicating that the device exhibits positive photoconductivity at low read voltages. At low source-drain voltages, the double layer effect caused by the electrolyte layer is not strong, and the stimulated current exhibits non-volatility. When the source-drain voltage is fixed at -1V and the read voltage is -7V, the device is applied with an intensity of 1mW / cm 2 A 1-second light pulse significantly suppressed the device's current level, indicating negative photoconductivity at high read voltages. Due to the low source-drain voltage, the post-stimulation current also exhibited non-volatile properties.

[0065] Figure 9 The postsynaptic current curves of the dynamically reconfigurable organic photosensitive field-effect transistor prepared in Example 2 with F8BT as the organic photosensitive electret layer and sodium alginate as the electrolyte layer at different source-drain voltages were obtained with a wavelength of 470 nm and a light intensity of 1 mW / cm 2 As can be seen from the figure, when the read voltage is fixed at 0V and the source-drain voltage is -1V, the intensity applied to the device is 1mW / cm 2 The light pulse of 1s was used to find that the current level of the device was obviously excited, and the current after stimulation was non-volatile. This phenomenon is consistent with Figure 8The conclusion is consistent with that of the device, indicating that the device exhibits positive photoconductivity at low read voltage, and the current after stimulation in the low source-drain voltage region is non-volatile. When the read voltage is fixed at 0V and the source-drain voltage is -2V, -3V, -4V, and -5V, the intensity applied to the device is 1mW / cm 2 A 1-second light pulse significantly suppressed the device's current level, indicating positive photoconductivity at low read voltages. The non-volatility of the post-stimulation current weakened with increasing read voltage. This is primarily due to the enhanced double-layer effect in the electrolyte layer caused by the increased source-drain voltage. The built-in electric field generated by the double-layer effect exerts an upward force on the holes trapped in the charge-trapping layer, causing them to continuously return to the conductive channel, resulting in an increase in the non-volatility of the post-stimulation current.

Claims

1. A dynamically reconfigurable organic photosensitive field effect transistor, characterized in that: The dynamically reconfigurable organic photosensitive field effect transistor comprises, from bottom to top, a gate, a gate insulating layer, an electrolyte layer, an organic photosensitive charge trapping layer, an organic photosensitive semiconductor layer, and a source-drain electrode, i.e., a source electrode and a drain electrode; the organic photosensitive charge trapping layer is made of an organic photosensitive electret material with a strong charge storage capacity, and the strong charge storage capacity means that the charge storage density of the organic photosensitive electret material exceeds 4×10 12 C / m 2 The electrolyte layer is prepared from a polyelectrolyte material, which is a natural water-soluble polymer material containing ionizable groups.

2. The dynamically reconfigurable organic photosensitive field effect transistor according to claim 1, characterized in that: The preparation material of the polyelectrolyte layer is selected from one or more of chitosan, sodium alginate and polyquaternium-11; the thickness of the film of the polyelectrolyte layer is 300-500nm.

3. The dynamically reconfigurable organic photosensitive field effect transistor according to claim 1, wherein: The organic photosensitive electret is prepared from one or more materials selected from PCBM, MEH-PPV, SY-PPV, PVK, F8BT, and PFO; and the thickness of the film of the organic photosensitive electret layer is 10 to 50 nm.

4. The dynamically reconfigurable organic photosensitive field effect transistor according to claim 1, wherein: The preparation material of the organic photosensitive semiconductor layer is selected from one or more of pentacene, P3HT, C8-BTBT, and DNTT; the thickness of the organic semiconductor layer is 40 to 60 nm.

5. The dynamically reconfigurable organic photosensitive field effect transistor according to claim 1, wherein: The absorption spectrum of the organic photosensitive electret is complementary to the absorption spectrum of the organic photosensitive semiconductor.

6. The dynamically reconfigurable organic photosensitive field effect transistor according to claim 1, wherein: The gate electrode is made of a material selected from highly doped silicon, Cu, Au, Ag or Pt.

7. The dynamically reconfigurable organic photosensitive field effect transistor according to claim 1, wherein: The gate insulating layer is made of any one of hafnium oxide, titanium oxide, zirconium oxide, silicon dioxide or aluminum oxide, and has a film thickness of 10 to 300 nm.

8. The dynamically reconfigurable organic photosensitive field effect transistor according to claim 1, wherein: The source-drain electrodes are grown on both sides of the conductive channel. The material used for the source-drain electrodes is one of Cu, Au or Pt. The thickness of the source-drain electrodes is 80-110 nm. The preparation method is magnetron sputtering or vacuum evaporation.

9. The dynamically reconfigurable organic photosensitive field effect transistor according to claim 1, wherein: The length of the conductive channel between the source and the drain is 50 to 200 μm, and the width of the conductive channel between the source and the drain is 1000 to 2000 μm.

10. The method for manufacturing the dynamically reconfigurable organic photosensitive field effect transistor according to claim 1, comprising the following steps: Step S1, dissolving the natural water-soluble polymer material in deionized water to prepare a solution with a concentration of 10 to 40 mg / mL, shaking and stirring in a cleaning machine for 2 to 3 hours, and then standing for 8 to 12 hours; Step S2, dissolving the organic photosensitive electret material with strong charge storage capacity in an organic solvent to prepare a solution with a concentration of 3 to 10 mg / mL, adding polytetrafluoroethylene magnets, heating and stirring on a heating platform for 2 to 3 hours, and then standing for 8 to 12 hours; Step S3, selecting highly doped silicon as the gate electrode and silicon dioxide as the gate insulating layer, with the thickness of the gate insulating layer being 50 to 300 nm; Step S4, ultrasonically cleaning the surface of the silicon wafer in step S3 using acetone, ethanol, and deionized water, respectively, for 5 to 10 minutes, and drying at 120° C. after cleaning; Step S5, treating the dried clean silicon wafer with ultraviolet ozone for 5 to 10 minutes; Step S6, forming an organic photosensitive electret film with a thickness of 10 to 50 nm using the organic photosensitive electret solution prepared in step S1 on the cleaned silicon wafer in step S5 by one or more methods selected from the group consisting of solution processing, vacuum evaporation, molecular beam epitaxy, sputtering, laser pulse deposition, and inkjet printing, and annealing the film in vacuum at 80° C. for 30 minutes; Step S7 , on the sample annealed in step S6 , an organic photosensitive semiconductor layer and a source-drain electrode are sequentially prepared by vacuum evaporation coating.

Images