A porous organic field effect transistor and a preparation method and application thereof

Abstract

The application discloses a kind of porous organic field effect transistor and its preparation method and application.The preparation method includes the following steps: porous dielectric layer is formed by femtosecond laser ablation on the surface of dielectric layer;During femtosecond laser processing, the moving speed of the stage is 10000-500000 μm / s;Porous organic semiconductor layer is formed on the surface of porous dielectric layer by template guiding effect;Source electrode and drain electrode are prepared on porous organic semiconductor layer.By means of femtosecond laser processing technology, by adjusting the moving speed of processing platform, single femtosecond laser pulse can be ablated with polymer dielectric layer, and the porous template obtained has the characteristics of smooth surface, few defects, uniform pore size, high pattern accuracy, controllable pattern, good device repeatability and other characteristics, and the final obtained organic field effect transistor exhibits excellent field effect transfer characteristic curve;The method is convenient and fast, and can be used for rapid preparation of high-performance gas sensing device, and has good universality.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of gas detection sensor, in particular to a porous organic field effect transistor and a preparation method and application thereof. BACKGROUND

[0002] Organic field effect transistor (OFET) is a kind of active device based on organic semiconductor material, which has the advantages of low cost, light weight, bendable, stretchable, etc., and has great application prospect in flexible display matrix, radio frequency electronic tags and flexible sensors. The special device structure of OFET can make the special gas molecules in the working environment of OFET have physical or chemical adsorption with the organic semiconductor layer in OFET, and then cause the change of the electrical properties of the device. This special phenomenon makes OFET be able to be used for preparing high-performance gas sensor devices and has been widely concerned by researchers.

[0003] In order to meet the needs of practical application, the device performance of OFET-based gas sensor still needs to be further improved. The main parameters for measuring its performance level are sensitivity, detection limit and gas selectivity, etc. Since the realization of OFET sensing function mainly depends on the interaction between gas molecules and conductive channel, many researchers are now working on preparing porous organic field effect transistor sensors with porous structure. The porous structure of such devices can enhance the contact between gas molecules and conductive channel, thereby significantly improving the sensing sensitivity of the device and detecting lower concentration of gas.(1: Lu J.J., Liu D.P., Zhou J.C., Chu Y.L., Chen Y.T., Wu X.H., Huang J. Adv. Funct. Mater., 2017, 27, 1700018.). But there is still a certain gap between the uniformity of the pore size, controllability of the porous pattern and repeatability of the device of the porous devices prepared by the currently reported methods and the requirements of practical application. Therefore, developing a method for efficiently and quickly preparing porous organic field effect transistor sensors with controllable porous pattern is an inevitable requirement for developing high-performance OFET gas sensors in the future.

[0004] Femtosecond laser processing technology is a new type of non-destructive cold processing technology. At present, femtosecond laser processing technology has problems such as processing residue, low pattern precision, etc. when applied to process organic polymer film, which cannot meet the processing requirements of the porous OFET dielectric layer. SUMMARY

[0005] The present application aims to overcome the above technical deficiencies, and provides a porous organic field effect transistor and a preparation method and application thereof, which solves the technical problems of poor pore size uniformity, controllability of porous pattern and repeatability of device of the porous organic field effect transistor sensors prepared in the prior art.

[0006] The first aspect of the present application provides a method for preparing a porous organic field effect transistor, comprising the following steps:

[0007] providing a substrate with a gate electrode layer;

[0008] forming a dielectric layer on the surface of the substrate with the gate electrode layer, and forming a porous dielectric layer by ablating the surface of the dielectric layer with a femtosecond laser; during the femtosecond laser processing, the moving speed of the stage is 10000-500000 μm / s;

[0009] forming a porous organic semiconductor layer on the surface of the porous dielectric layer by template guidance;

[0010] preparing a source electrode and a drain electrode on the porous organic semiconductor layer to obtain a porous organic field effect transistor.

[0011] The second aspect of the present application provides a porous organic field effect transistor, which is obtained by the method for preparing a porous organic field effect transistor provided in the first aspect of the present application.

[0012] The third aspect of the present application provides a gas sensor, which is the porous organic field effect transistor provided in the second aspect of the present application; wherein the porous organic semiconductor layer is a porous gas-sensitive organic semiconductor layer.

[0013] Compared with the prior art, the present application has the following beneficial effects:

[0014] By means of femtosecond laser processing technology, the present application can make a single femtosecond laser pulse ablate the polymer dielectric layer by adjusting the moving speed of the processing platform, so that the obtained porous template has the characteristics of smooth surface, few defects, uniform pore size, high pattern precision (pore size less than 2 μm, pore spacing adjustable between 3 μm and 50 μm, clear and smooth edge of the pore pattern), controllable pattern, good device repeatability, etc., and the finally obtained organic field effect transistor exhibits excellent field effect transfer characteristic curve; at the same time, the method is convenient and fast, and can be used for rapidly preparing high-performance gas sensor devices; since the femtosecond laser has very high instantaneous power, it can be used to prepare porous patterns on most dielectric materials, and can be applied to field effect transistor devices containing different dielectric layer materials, and has good universality. BRIEF DESCRIPTION OF DRAWINGS

[0015] Figure 1 It is a scanning electron microscope photo of the surface of the PDMS with a stage moving speed of 3000 μm / s;

[0016] Figure 2 It is a scanning electron microscope photo of the surface of the PDMS with a stage moving speed of 50000 μm / s;

[0017] Figure 3 Transfer curves of the organic field effect transistor devices based on the porous PDMS dielectric layer processed at the stage movement speed of 3000 μm / s and 50000 μm / s;

[0018] Figure 4 Scanning electron microscope image of the PDMS surface with a pore spacing of 3 μm;

[0019] Figure 5 Scanning electron microscope image of the PDMS surface with a pore spacing of 5 μm;

[0020] Figure 6 Scanning electron microscope image of the PDMS surface with a pore spacing of 10 μm;

[0021] Figure 7 Scanning electron microscope image of the PDMS surface with a pore spacing of 20 μm;

[0022] Figure 8 Scanning electron microscope image of the PDMS surface with a pore spacing of 50 μm;

[0023] Figure 9 Atomic force microscope image of the surface of the organic polymer semiconductor spin-coated on the porous PDMS;

[0024] Figure 10 Curve of the source-drain current of the organic field effect transistor sensor without a pore structure and the porous organic field effect transistor sensor with a pore spacing of 3 μm over time;

[0025] Figure 11 Current response result graph of the PDPP-TT sensor device with different pore spacings to 1 ppm ammonia gas;

[0026] Figure 12 Current response result graph of the IIDDT sensor device with different pore spacings to 1 ppm ammonia gas. DETAILED DESCRIPTION

[0027] In order to make the objects, technical solutions and advantages of the present application clearer, the present application will be further described in detail below with reference to the drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and should not be used to limit the present application.

[0028] The first aspect of the present application provides a preparation method of a porous organic field effect transistor, comprising the following steps:

[0029] S1, providing a substrate with a gate electrode layer;

[0030] S2, forming a dielectric layer on the surface of the substrate with the gate electrode layer, and forming a porous dielectric layer by ablating the surface of the dielectric layer with a femtosecond laser; those skilled in the art should understand that the porous dielectric layer is formed on the surface of the gate electrode layer; during the femtosecond laser processing, the moving speed of the objective table is 10000-500000 μm / s, further 30000-100000 μm / s, and more further 30000-50000 μm / s. By adjusting the moving speed of the objective table, the single laser pulse can interact with the PDMS dielectric layer, so that the hole pattern with different topographies is processed on the surface of the PDMS.

[0031] S3, forming a porous organic semiconductor layer on the surface of the porous dielectric layer by template guiding action.

[0032] S4, preparing a source electrode and a drain electrode on the porous organic semiconductor layer to obtain a porous organic field effect transistor.

[0033] The porous dielectric layer directly prepared by the existing femtosecond laser processing method has a rough surface and more residues, and since the generation of the conductive channel in the organic field effect transistor requires that the surface of the dielectric layer has high flatness and low defect density, the obtained porous dielectric layer is not conducive to the preparation of high-performance organic field effect transistors. The inventor found in the subsequent test process that by adjusting the moving speed of the processing platform, the single femtosecond laser pulse can ablate the polymer dielectric layer, the obtained porous template has the characteristics of smooth surface, few defects, uniform pore size, controllable pattern, high precision and good device repeatability, and finally the obtained organic field effect transistor exhibits excellent field effect transfer characteristic curve; at the same time, the method is convenient and fast, and can be used for rapidly preparing high-performance gas sensing devices; since the femtosecond laser has very high instantaneous power, it can be used to prepare porous topographies on most dielectric materials, and can be applied to field effect transistor devices containing different dielectric layer materials, and has good universality.

[0034] In the present application, the substrate is at least one of plastic, glass, ceramic, and silicon wafer.

[0035] In the present application, the material forming the gate electrode layer, the source electrode and the drain electrode is at least one of metal, ceramic, alloy, metal oxide, heavily doped semiconductor, and conductive polymer; wherein the metal is at least one of gold, silver, aluminum or copper; the ceramic is a silicon wafer; the alloy material is at least one of magnesium-silver alloy, platinum-gold alloy or nickel-zinc alloy; the metal oxide is at least one of indium tin oxide, manganese dioxide or lead dioxide; the heavily doped semiconductor is at least one of phosphorus-doped silicon, boron-doped silicon or arsenic-doped silicon, and the doping mass percentage of phosphorus, boron or arsenic is 1-3%; the conductive polymer is at least one of polyaniline, polypyrrole or polythiophene.

[0036] In the present application, the thickness of the substrate is 10 μm to 800 μm, for example, it can be 10 μm, 50 μm, 100 μm, 300 μm, 500 μm, 800 μm, etc., but is not limited to the listed values, and other values not listed in the range are also applicable; the thickness of the gate electrode layer is 100 nm to 100 μm, for example, it can be 100 nm, 300 nm, 1 μm, 5 μm, 10 μm, 50 μm, 100 μm, etc., but is not limited to the listed values, and other values not listed in the range are also applicable; the thickness of the source electrode and the drain electrode is 10 to 300 nm, for example, it can be 10 nm, 30 nm, 50 nm, 100 nm, 200 nm, 300 nm, etc., but is not limited to the listed values, and other values not listed in the range are also applicable.

[0037] In the present application, the gate electrode layer, the source electrode and the drain electrode are obtained by vacuum thermal evaporation, magnetron sputtering or plasma enhanced chemical vapor deposition.

[0038] In the present application, the material forming the porous dielectric layer is at least one of silicon dioxide, octadecyltrichlorosilane monolayer modified silicon dioxide, silicon nitride or organic insulating material. Further, the organic insulating material is at least one of polydimethylsiloxane, polymethyl methacrylate, polystyrene or polyvinyl phenol.

[0039] In the present application, the thickness of the porous dielectric layer material is 0.1 to 5 μm, for example, it can be 0.1 μm, 0.5 μm, 1 μm, 1.5 μm, 2 μm, 5 μm, etc., but is not limited to the listed values, and other values not listed in the range are also applicable.

[0040] In the present application, the dielectric layer is formed on the surface of the substrate with the gate electrode layer by plasma enhanced chemical vapor deposition, spin coating, film spinning, thermal oxidation or vacuum evaporation.

[0041] In some embodiments of the present application, the surface has a heavily doped silicon with a thickness of 50 to 300 nm of silicon dioxide as the substrate and the gate electrode layer. Further, the thickness of the heavily doped silicon is 300 to 800 μm, for example, it can be 300 μm, 400 μm, 500 μm, 600 μm, 700 μm, 800 μm, etc., but is not limited to the listed values, and other values not listed in the range are also applicable; the doping mass percentage of phosphorus, boron or arsenic in the heavily doped silicon is 1 to 3%, for example, it can be 1%, 1.5%, 2%, 2.5%, 3%, etc., but is not limited to the listed values, and other values not listed in the range are also applicable.

[0042] In the present application, in the femtosecond laser processing process, the femtosecond laser repetition frequency is 1 kHz-10 MHz, for example, it can be 1 kHz, 5 kHz, 10 kHz, 100 kHz, 200 kHz, 500 kHz, 1 MHz, 2 MHz, 5 MHz, 10 MHz, etc., but not limited to the listed values, other values not listed in this range are also applicable; the femtosecond laser pulse width is 5-1000 fs, for example, it can be 5 fs, 8 fs, 50 fs, 100 fs, 150 fs, 188 fs, 500 fs, 800 fs, 1000 fs, but not limited to the listed values, other values not listed in this range are also applicable; the femtosecond laser energy density is 0.1 J / cm 2 -100 J / cm 2 , for example, it can be 0.1 J / cm 2 , 0.4 J / cm 2 , 0.46 J / cm 2 , 0.5 J / cm 2 , 2 J / cm 2 , 10 J / cm 2 , 20 J / cm 2 , 50 J / cm 2 , 80 J / cm 2 , 100 J / cm 2 , etc., but not limited to the listed values, other values not listed in this range are also applicable; the center wavelength is 50-2000 nm, for example, it can be 50 nm, 200 nm, 300 nm, 500 nm, 1080 nm, 1500 nm, 2000 nm, etc., but not limited to the listed values, other values not listed in this range are also applicable; the numerical aperture of the objective lens is NA 0.05-NA 2.0, for example, it can be NA 0.05, NA 0.1, NA 0.2, NA 0.25, NA 0.4, NA 0.45, NA 1.0, NA 1.5, NA 2.0, etc., but not limited to the listed values, other values not listed in this range are also applicable.

[0043] In some embodiments of the present application, the step of forming a porous dielectric layer by ablating the surface of the dielectric layer with a femtosecond laser includes: placing a substrate with a gate electrode layer and a dielectric layer on a movable stage, and focusing a femtosecond laser through an objective lens onto the surface of the dielectric layer, moving the stage, and scanning the surface of the dielectric layer with the femtosecond laser, adjusting the parameters of the femtosecond laser and the moving speed of the stage, ablating a series of hole structures on the surface of the dielectric layer to form a porous dielectric layer.

[0044] In the present application, the porous organic semiconductor layer is a porous gas-sensitive organic semiconductor layer. The material forming the porous gas-sensitive organic semiconductor layer is a material capable of adsorbing at least one of ammonia, hydrogen chloride, nitrogen dioxide, hydrogen sulfide, sulfur dioxide, chlorine or hydrazine hydrate vapor in a physical or chemical adsorption manner. For example, the material forming the porous gas-sensitive organic semiconductor layer can be a material having the following structure:

[0045]

[0046] wherein n is 100-500.

[0047] In the present application, the thickness of the porous organic semiconductor layer is 10-100 nm, for example, 10 nm, 20 nm, 30 nm, 40 nm, 50 nm, 60 nm, 70 nm, 80 nm, 90 nm, 100 nm, etc., but is not limited to the listed values, and other values not listed in this range are also applicable.

[0048] In the present application, the porous gas-sensitive organic semiconductor layer is formed on the surface of the porous dielectric layer by spin coating, pulling or evaporation.

[0049] The second aspect of the present application provides a porous organic field effect transistor, which is obtained by the preparation method of the porous organic field effect transistor provided in the first aspect of the present application.

[0050] wherein the pore spacing of the porous dielectric layer is 1-50 μm, further 3-10 μm, and more further 3-5 μm.

[0051] The third aspect of the present application provides a gas sensor, which is the porous organic field effect transistor provided in the second aspect of the present application; wherein the porous organic semiconductor layer is a porous gas-sensitive organic semiconductor layer.

[0052] Example 1

[0053] (1) First, a phosphorus-doped silicon wafer is cut into small pieces of 1.3 cm x 1.3 cm (the thickness of the silicon is 500 μm, and the mass concentration of phosphorus doping is 1.5%), and a silicon dioxide layer formed by thermal oxidation is deposited on the surface of the silicon wafer, with a thickness of 300 nm. The cut substrate is ultrasonically cleaned with ultrapure water, acetone and isopropyl alcohol, dried with nitrogen, and then fixed in a spin coater, followed by spin coating a layer of 1.5 μm of polydimethylsiloxane (PDMS) on the silicon wafer and heating and curing on a hot stage for 1 h.

[0054] (2) Put the device prepared in step (1) on the femtosecond laser processing stage and fix it, use an objective lens with a numerical aperture of NA 0.4 to guide the femtosecond laser beam to the surface of the device, the wavelength of the femtosecond laser is 1080 nm, the repetition rate is 10 kHz, the pulse width is 188 fs, and the laser energy density is 0.46 J / cm 2 . Figure 1 is a scanning electron microscope photo of the PDMS surface with a stage moving speed of 3000 μm / s; Figure 2 is a scanning electron microscope photo of the PDMS surface with a stage moving speed of 50000 μm / s; By comparison, it can be seen that when the stage moving speed is large, the porous PDMS dielectric layer processed by the laser has a smooth surface and almost no residual material, and when the stage moving speed is small, the processed dielectric layer has a very rough surface morphology and more processing residual substances.

[0055] (3) Put the device prepared in step (2) on the spin coater and fix it, and spin coat a layer of polypyrrole derivative PDPP-TT on the surface at a speed of 3000 rpm, with a thickness of 30 nm.

[0056] (4) Put the device prepared in step (3) in a high vacuum thermal evaporation film plating machine, use a mechanical pump and a molecular pump to pump the vacuum degree to 5×10 -4 pa below, and evaporate a layer of 30 nm of gold, to complete the porous organic field effect transistor provided by the application. Among them, the insulating layer is silicon dioxide and porous PDMS, the organic semiconductor layer is PDPP-TT, and the source and drain electrode is gold.

[0057] Put the porous organic field effect transistor obtained in Example 1 on the semiconductor test probe station and fix it, and test its field effect transfer curve. Figure 3 is the transfer curve of the organic field effect transistor device based on the porous PDMS dielectric layer processed with a stage moving speed of 3000 μm / s and 50000 μm / s. By comparison, it can be found that the transfer characteristics of the transistor device based on the dielectric layer in Figure 1 are not obvious, and the device almost does not show transistor characteristics. While the device based on the dielectric layer in Figure 2 shows a typical transfer characteristic curve, and the curve is smooth, indicating that the porous dielectric layer prepared by the method has very good surface morphology and can be used to prepare high-performance organic field effect transistor devices.

[0058] Example 2

[0059] (1) First, phosphorus-doped silicon wafers were cut into small pieces of 1.3 cm x 1.3 cm (silicon thickness of 500 μm, phosphorus doping mass concentration of 1.5%) as the small substrate, and a thermal oxidation formed silicon dioxide layer was deposited on the surface of the silicon wafer, with a thickness of 300 nm. The cut substrate was ultrasonically cleaned with ultrapure water, acetone, and isopropyl alcohol, and then dried with nitrogen and fixed in a spin coater. Then, 1.5 μm of polydimethylsiloxane (PDMS) was spin-coated on the silicon wafer, and the silicon wafer was heated and cured on a hot stage for 1 h.

[0060] (2) The device prepared in step (1) was fixed on a femtosecond laser processing stage, and a femtosecond laser beam with a numerical aperture of NA 0.4 was introduced into the surface of the device using an objective lens. The wavelength of the femtosecond laser was 1080 nm, the repetition rate was 10 kHz, the pulse width was 188 fs, and the laser energy density was 0.46 J / cm 2 . The stage was moved at different speeds (30000-500000 μm / s) using a computer to process different hole patterns on the surface of the PDMS. Figure 4 is a scanning electron microscope photo of the surface of the PDMS with a hole spacing of 3 μm (stage moving speed of 30000 μm / s); Figure 5 is a scanning electron microscope photo of the surface of the PDMS with a hole spacing of 5 μm (stage moving speed of 50000 μm / s); Figure 6 is a scanning electron microscope photo of the surface of the PDMS with a hole spacing of 10 μm (stage moving speed of 100000 μm / s); Figure 7 is a scanning electron microscope photo of the surface of the PDMS with a hole spacing of 20 μm (stage moving speed of 200000 μm / s); Figure 8 is a scanning electron microscope photo of the surface of the PDMS with a hole spacing of 50 μm (stage moving speed of 500000 μm / s). It can be seen that the smaller the hole spacing, the greater the hole density on the surface of the PDMS. Figures 4 to 8

[0061] (3) The device prepared in step (2) was fixed in a spin coater, and a layer of polypyrrole derivative PDPP-TT was spin-coated on the surface at a speed of 3000 rpm, with a thickness of 30 nm. Due to the guiding effect of the porous PDMS layer, the organic semiconductor PDPP-TT spin-coated thereon also formed the same hole pattern. Figure 9 is an atomic force microscope photo of the surface of the organic polymer semiconductor spin-coated on the porous PDMS (stage moving speed of 30000 μm / s), and it can be found that the organic semiconductor layer also formed the same porous pattern as the PDMS layer.

[0062] ​(4) Put the device prepared in step (3) into a high vacuum thermal evaporation coating machine, use a mechanical pump and a molecular pump to draw the vacuum degree to 5x10 -4 pa and evaporate a 30 nm layer of gold, to complete the porous organic field effect transistor sensor provided by the application. The insulating layer is silicon dioxide and porous PDMS or silicon dioxide and PDMS that has not been processed by laser irradiation, the organic semiconductor layer is PDPP-TT, and the source-drain electrode is gold.

[0063] Example 3

[0064] Different concentrations of ammonia were detected using different organic field effect transistor sensors. First, the organic field effect transistor sensor obtained in Example 2 was placed on a semiconductor test platform, and a source-drain voltage and a gate voltage were applied. When the source-drain current was stable, ammonia with concentrations of 100 ppb, 500 ppb, 1 ppm, 5 ppm and 10 ppm was introduced. The source-drain current-time curves of the organic field effect transistor sensor without a pore structure and the porous organic field effect transistor sensor with a pore spacing of 3 μm are shown in Figure 10 When the ammonia was introduced, the source-drain current of the porous organic field effect transistor sensor with a pore spacing of 3 μm rapidly decreased, and the decrease was large. In contrast, the current of the organic field effect transistor sensor without a pore structure decreased slowly, and the decrease was small. Therefore, the organic field effect transistor sensor based on a porous PDMS dielectric layer has higher sensitivity when detecting ammonia.

[0065] Example 3 Figure 11 The organic field effect transistor sensors with different pore spacings in Example 2 were placed on a semiconductor test platform, and a source-drain voltage and a gate voltage were applied. When the current was stable, 1 ppm of ammonia was introduced. The current responses of the sensors with different pore spacings to 1 ppm of ammonia are shown in As the pore spacing decreased, the response of the device to 1 ppm of ammonia gradually increased, indicating that the ammonia sensing sensitivity of the device can be regulated by changing the density of the pores in the device.

[0066] Example 4

[0067] (1) First, a phosphorus-doped silicon wafer was cut into small 1.3 cm x 1.3 cm substrates (the silicon thickness was 500 μm, and the mass concentration of phosphorus doping was 1.5%). A silicon dioxide layer formed by thermal oxidation was deposited on the surface of the silicon wafer, and the thickness of the layer was 300 nm. The cut substrates were ultrasonically cleaned with ultrapure water, acetone and isopropyl alcohol, dried with nitrogen, and then fixed in a spin coater. Subsequently, a 1.5 μm layer of polydimethylsiloxane (PDMS) was spin-coated on the silicon wafer, and the wafer was heated and cured on a hot stage for 1 h.

[0068] (2) The device prepared in step (1) is placed on a femtosecond laser processing stage and fixed, and a femtosecond laser beam is introduced into the surface of the device using an objective lens with a numerical aperture of NA 0.4, the wavelength of the femtosecond laser is 1080 nm, the repetition rate is 10 kHz, the pulse width is 188 fs, and the laser energy density is 0.46 J / cm 2 The computer-controlled stage is used to move at different speeds (30000 μm / s, 50000 μm / s, 100000 μm / s, 200000 μm / s, 500000 μm / s), and a hole pattern with different intervals can be processed on the surface of the PDMS.

[0069] (3) The device prepared in step (2) is placed in a spin coater and fixed, and a layer of polythiophene derivative IIDD T with a thickness of 30 nm is spin-coated on the surface at a speed of 3000 rpm. Due to the guiding effect of the porous PDMS layer, the organic semiconductor IIDD T spin-coated thereon also forms the same hole pattern.

[0070] (4) The device prepared in step (3) is placed in a high-vacuum thermal evaporation film plating machine, a mechanical pump and a molecular pump are used to pump the vacuum degree to 5×10 -4 Pa, and a layer of 30 nm of gold is evaporated, and the porous organic field effect transistor sensor based on IIDD T is completed. Among them, the insulating layer is silicon dioxide and porous PDMS or silicon dioxide and PDMS not subjected to laser irradiation processing, the organic semiconductor layer is IIDD T, and the source-drain electrode is gold.

[0071] The IIDD T organic field effect transistor sensor device with different hole intervals is placed on a semiconductor test platform, and a source-drain voltage and a gate voltage are applied, and 1 ppm of ammonia gas is introduced when the current is stable. The current response of the sensor device with different hole intervals to 1 ppm of ammonia gas is shown in Figure 12 It can be seen that as the hole interval decreases, the response of the device to 1 ppm of ammonia gas gradually increases, indicating that changing the density of holes in the device can regulate the ammonia gas sensing sensitivity of the device, and indicating that this method has an enhancing effect on the ammonia gas sensing sensitivity of different organic semiconductor devices.

[0072] The specific embodiments of the application described above do not constitute a limitation on the scope of protection of the application. Any various other corresponding changes and modifications made in accordance with the technical concept of the application shall be included in the scope of protection of the claims of the application.

Claims

1. A method for fabricating a porous organic field-effect transistor, characterized in that, Includes the following steps: Provide a substrate with a gate electrode layer; A dielectric layer is formed on the surface of the substrate having a gate electrode layer, and a porous dielectric layer is formed by ablation of the dielectric layer surface by a femtosecond laser. A porous organic semiconductor layer is formed on the surface of the porous dielectric layer by template guidance; Source and drain electrodes are fabricated on the porous organic semiconductor layer to obtain a porous organic field-effect transistor; wherein, The step of forming a porous dielectric layer by ablation of the dielectric layer surface using a femtosecond laser includes: placing a substrate having a gate electrode layer and a dielectric layer on a movable stage; focusing a femtosecond laser onto the dielectric layer surface through an objective lens; moving the stage to allow the femtosecond laser to scan the dielectric layer surface; adjusting the femtosecond laser parameters and the stage movement speed to ablate a series of pore structures on the dielectric layer surface, thus forming a porous dielectric layer; during the femtosecond laser processing, the stage movement speed is 10000~500000 µm / s, the femtosecond laser repetition rate is 1kHz~10MHz, the femtosecond laser pulse width is 5~1000fs, and the femtosecond laser energy density is 0.1J / cm². 2 ~100J / cm 2 The center wavelength is 50~2000nm, and the numerical aperture of the objective lens is NA0.05~NA2.

0.

2. The method for fabricating a porous organic field-effect transistor according to claim 1, characterized in that, The stage moves at a speed of 30,000 to 50,000 µm / s.

3. The method for fabricating a porous organic field-effect transistor according to claim 1, characterized in that, The material forming the porous dielectric layer is at least one of silicon dioxide, silicon dioxide monomolecule modified with octadecyltrichlorosilane, silicon nitride, or organic insulating material.

4. The method for fabricating a porous organic field-effect transistor according to claim 1, characterized in that, The porous organic semiconductor layer is a porous gas-sensitive organic semiconductor layer.

5. The method for fabricating a porous organic field-effect transistor according to claim 4, characterized in that, The material forming the porous gas-sensitive organic semiconductor layer is a material that can adsorb at least one gas from ammonia, hydrogen chloride, nitrogen dioxide, hydrogen sulfide, sulfur dioxide, chlorine or hydrazine hydrate vapor by physical or chemical adsorption.

6. The method for fabricating a porous organic field-effect transistor according to claim 1, characterized in that, A dielectric layer is formed on the surface of the substrate with the gate electrode layer by means of plasma-enhanced chemical vapor deposition, spin coating, spin casting, thermal oxidation or vacuum evaporation; a porous organic semiconductor layer is formed on the surface of the porous dielectric layer by means of spin coating, dip coating or evaporation.

7. A porous organic field-effect transistor, characterized in that, The porous organic field-effect transistor is obtained by the fabrication method of the porous organic field-effect transistor according to any one of claims 1 to 6.

8. A gas sensor, characterized in that, The gas sensor is the porous organic field-effect transistor of claim 7; wherein the porous organic semiconductor layer is a porous gas-sensitive organic semiconductor layer.

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