A polymer organic optoelectronic transistor, its preparation method and application

Abstract

The present invention discloses a polymer organic optoelectronic transistor, a preparation method and an application thereof. The polymer organic optoelectronic transistor includes: a substrate, a dielectric layer, an organic semiconductor thin film, a source electrode and a drain electrode. The dielectric layer covers the substrate, the organic semiconductor thin film covers the dielectric layer, and the source electrode and the drain electrode are respectively located on the organic semiconductor thin film. Among them, the organic semiconductor thin film includes: polar molecules and crystalline polymer organic molecules. The present invention shortens the light response time of the polymer organic optoelectronic transistor. By doping polar molecules, the light response time of the polymer organic optoelectronic transistor prepared from polymer organic molecules is shortened from more than 580 s to as fast as 38.27 ms at the fastest. It has good stability, and the polymer organic optoelectronic transistor has high sensitivity, responsivity and detectivity.

Description

Technical Field

[0001] The present invention belongs to the technical field of organic optoelectronic transistor manufacturing, and specifically relates to a polymer organic optoelectronic transistor, a preparation method thereof, and an application thereof. Background Art

[0002] Organic semiconductor materials usually have strong absorption in the ultraviolet, visible, and near-infrared regions, and the absorption coefficient can exceed 10 5 cm -1 , and their good absorption characteristics make organic semiconductor materials very suitable for the preparation of optoelectronic devices. At present, organic semiconductor materials mainly include small-molecule organic semiconductor materials and polymer organic semiconductor materials. Among them, polymer organic semiconductor materials are composed of multiple repeating units, have a long molecular chain, are in a chain structure, and have advantages such as good solubility, flexibility, and low cost. Compared with the organic optoelectronic transistors prepared from small-molecule organic semiconductor materials, the organic optoelectronic transistors prepared by covering a flexible dielectric layer on a flexible substrate with polymer organic semiconductor materials have better flexibility (van Neer, Paul LMJ, et al. Flexible large-area ultrasound arrays for medical applications made using embossed polymer structures. Nature communications 15.1 (2024): 2802; Zhao, Pengfei, et al. Transfer‐Printing of Insoluble Conducting Polymer for Soft 3D Conformal All‐Organic Transistors. Small (2024): 2309263.), and are more excellent in terms of bendability, stretchability, or foldability, etc., can achieve full flexibility, and are suitable for more complex working environments on the surface; in addition, the organic optoelectronic transistors prepared by covering a rigid dielectric layer on a rigid substrate with polymer organic semiconductor materials have more significant advantages in mechanical stability, thermal stability, processing compatibility, and reliability, etc., and are suitable for the manufacture and large-scale production of high-performance electronic devices.

[0003] However, the photoresponse time of the organic optoelectronic transistors prepared from polymer organic semiconductor materials is relatively long, and even some of the organic optoelectronic transistors prepared from polymer organic semiconductor materials have a light synaptic performance with light saturation (light synaptic performance with light saturation: the performance that the organic optoelectronic transistor cannot reach the current peak after long-term illumination).

[0004] Generally, the strategies for shortening the light response time of organic optoelectronic transistors mainly achieve this through methods such as designing and synthesizing new materials and constructing heterojunctions. There are problems such as a single design method and complex operating processes. Therefore, developing a method with simple operation, without affecting the performance of the original device, and shortening the light response time is of great significance and leading role for the research of polymer organic optoelectronic devices. Summary of the Invention

[0005] In view of the deficiencies of the prior art, the object of the present invention is to provide a polymer organic optoelectronic transistor.

[0006] Another object of the present invention is to provide a preparation method of a polymer organic optoelectronic transistor. This preparation method improves the dielectric constant of the organic semiconductor thin film and reduces the exciton binding energy by doping polar molecules with high dielectric performance, thereby achieving a fast light response of the polymer organic optoelectronic transistor.

[0007] Another object of the present invention is to provide an application of a polymer organic optoelectronic transistor as a photosensor device.

[0008] The object of the present invention is achieved through the following technical solutions.

[0009] A polymer organic optoelectronic transistor includes: a substrate, a dielectric layer, an organic semiconductor thin film, a source electrode, and a drain electrode. The dielectric layer covers the substrate, the organic semiconductor thin film covers the dielectric layer, and the source electrode and the drain electrode are respectively located on the organic semiconductor thin film. Among them, the organic semiconductor thin film includes: polar molecules and crystalline polymer organic molecules. The polymer organic molecules are one of PDVT-10, P3HT, and DPPT-TT; the polar molecules are one of TPBi, TmPyPB, and TPBTP. By mass, the ratio of polymer organic molecules to polar molecules is 10:(0.01~1).

[0010] In the above technical solution, the substrate is a rigid substrate or a flexible substrate. The rigid substrate is a silicon wafer or indium tin oxide (ITO) conductive glass, and the flexible substrate is a polydimethylsiloxane (PDMS) sheet or a polyimide (PI) sheet.

[0011] In the above technical solution, the dielectric layer is a rigid dielectric layer or a flexible dielectric layer. The rigid dielectric layer is SiO 2 layer or Al 2 O 3 layer, and the flexible dielectric layer is a polymethyl methacrylate (PMMA) layer or a polyvinyl alcohol (PVA) layer;

[0012] In the above technical solution, the thickness of the organic semiconductor thin film is 5~200 nm.

[0013] In the above technical solution, the thickness of the source electrode is 10-100 nm, and the thickness of the drain electrode is 10-100 nm.

[0014] In the above technical solution, the thickness of the dielectric layer is 5-300 nm.

[0015] In the above technical solution, the source electrode is a metal electrode, a conductive polymer electrode or a carbon electrode, the drain electrode is a metal electrode, a conductive polymer electrode or a carbon electrode, the metal electrode is one of a gold electrode, a silver electrode and an aluminum electrode, the conductive polymer electrode is one of a poly(3,4-ethylenedioxythiophene) poly(styrenesulfonate) electrode and a polyaniline electrode, and the carbon electrode is a carbon nanotube electrode.

[0016] In the polymer organic optoelectronic transistor, by mass fraction, the ratio of the polymer organic molecule to the polar molecule is 10:(0.05-0.4), more preferably 10:(0.06-0.3), still more preferably 10:(0.07-0.2), and even more preferably 10:(0.08-0.15).

[0017] The preparation method of the above polymer organic optoelectronic transistor includes the following steps:

[0018] Step 1: Disperse the polymer organic molecule in chlorobenzene to obtain a mixture, and mix the mixture with the polar molecule to obtain an organic semiconductor solution. Among them, by mass fraction, the ratio of the polymer organic molecule to the polar molecule is 10:(0.01-1), the polymer organic molecule is one of PDVT-10, P3HT and DPPT-TT; the polar molecule is one of TPBi, TmPyPB and TPBTP.

[0019] In the step 1, the structural formula of the PDVT-10 is , n represents the degree of polymerization, and the number average molecular weight (M n )>50k.

[0020] In the step 1, the structural formula of the P3HT is , n represents the degree of polymerization, and the number average molecular weight (M n )>20k.

[0021] In the step 1, the structural formula of the DPPT-TT is , n represents the degree of polymerization, and the number average molecular weight (M n )>20k.

[0022] In the step 1, the structural formula of the TPBi is .

[0023] In the step 1, the structural formula of the TmPyPB is .

[0024] In the step 1, the structural formula of the TPBTP is .

[0025] In the step 1, the concentration of the polymer organic molecules in the mixture is 5-25 mg / mL.

[0026] In the step 1, by mass, the ratio of the polymer organic molecules to the polar molecules is 10:(0.05-0.4), more preferably 10:(0.06-0.3), still more preferably 10:(0.07-0.2), and even more preferably 10:(0.08-0.15).

[0027] Step 2: Prepare a substrate covered with a dielectric layer, perform oxygen plasma treatment on the dielectric layer on the substrate, spin-coat an organic semiconductor solution on the dielectric layer of the substrate, heat and keep warm at 130-150 °C for 0.5-1 h, cool to room temperature, obtain an organic semiconductor thin film on the dielectric layer, and set a source electrode and a drain electrode on the surface of the organic semiconductor thin film to obtain a polymer organic optoelectronic transistor.

[0028] In the step 2, the power of the oxygen plasma treatment is 20-60 W, and the time of the oxygen plasma treatment is 60-300 s.

[0029] In the step 2, the rotation speed of the spin-coating is 1000-6000 r / s, and the time of the spin-coating is 30-100 s.

[0030] In the step 2, a source electrode and a drain electrode are set on the surface of the organic semiconductor thin film by evaporation.

[0031] Application of a polymer organic optoelectronic transistor as a photosensor device.

[0032] Compared with the prior art, the present invention has the following beneficial effects:

[0033] The present invention shortens the light response time of the polymer organic optoelectronic transistor. By doping polar molecules, the light response time of the polymer organic optoelectronic transistor prepared from polymer organic molecules is shortened from more than 580 s to as fast as 38.27 ms at the fastest. It has good stability, and the polymer organic optoelectronic transistor has high sensitivity, responsivity and detectivity. Description of the drawings

[0034] Figure 1 It is the main structural view of the polymer organic optoelectronic transistor;

[0035] Figure 2 It is the ultraviolet absorption spectra of the organic semiconductor thin film obtained in step 2 of Example 2 and Comparative Example 1 and the polar molecule thin film of Comparative Example 2;

[0036] Figure 3 X-ray diffraction spectra of the organic semiconductor thin films obtained in Step 2 for Examples 2 to 4 and Comparative Example 1;

[0037] Figure 4 Atomic force microscope images of the organic semiconductor thin films, where (a) is Comparative Example 1 and (b) is Example 2;

[0038] Figure 5 Capacitance diagrams (a) and dielectric constant diagrams (b) of the organic semiconductor thin films obtained in Step 2 for Examples 2 to 4 and Comparative Example 1;

[0039] Figure 6 Photoluminescence spectra of the organic semiconductor thin films obtained in Step 2 for Example 2 and Comparative Example 1;

[0040] Figure 7 Fluorescence spectra of the organic semiconductor thin films, where (a) is Comparative Example 1, (b) is Example 2, (c) is Example 3, and (d) is Example 4;

[0041] Figure 8 Transfer curves of the polymer organic optoelectronic transistors obtained for Examples 2 to 4 and Comparative Example 1 under dark conditions;

[0042] Figure 9 Transfer curves of the polymer organic optoelectronic transistors under dark conditions or under ultraviolet light irradiation with different light intensities, where (a) is Comparative Example 1 and (b) is Example 2;

[0043] Figure 10 Output curves of the polymer organic optoelectronic transistors, where (a) is Comparative Example 1 and (b) is Example 2;

[0044] Figure 11 Current-time curves of the polymer organic optoelectronic transistors, where (a) is Comparative Example 1 and (b) is Example 2;

[0045] Figure 12 Current-time curves of the continuous light response of the polymer organic optoelectronic transistors obtained for Example 2 and Comparative Example 1;

[0046] Figure 13 Sensitivity diagrams of the polymer organic optoelectronic transistors obtained for Comparative Example 1;

[0047] Figure 14 Responsivity diagrams of the polymer organic optoelectronic transistors obtained for Comparative Example 1;

[0048] Figure 15 Specific detectivity diagrams of the polymer organic optoelectronic transistors obtained for Comparative Example 1;

[0049] Figure 16 Sensitivity diagram of the polymer organic optoelectronic transistor obtained in Example 2;

[0050] Figure 17 Responsivity diagram of the polymer organic optoelectronic transistor obtained in Example 2;

[0051] Figure 18 Specific detectivity diagram of the polymer organic optoelectronic transistor obtained in Example 2.

[0052] Wherein, 1: Substrate, 2: Dielectric layer, 3: Organic semiconductor thin film, 4: Source electrode, 5: Drain electrode. Specific implementation mode

[0053] The technical solution of the present invention will be further described in detail below with reference to the accompanying drawings and embodiments.

[0054] In the following examples, the structural formula of TPBi is and it is purchased from Shanghai Macklin Biochemical Co., Ltd.

[0055] In the following examples, the structural formula of PDVT-10 is and the number average molecular weight (M n ) > 50k, and it is purchased from Shanghai Macklin Biochemical Co., Ltd.

[0056] In the following examples, the electrical properties were tested using an Agilent B1500 type electrical property test system under 365 nm ultraviolet light irradiation.

[0057] Examples 1 - 4

[0058] A preparation method of a polymer organic optoelectronic transistor, comprising the following steps:

[0059] Step 1, uniformly disperse the polymer organic molecules in chlorobenzene to obtain a mixture, and add a polar molecule to the mixture to obtain an organic semiconductor solution. Among them, by mass fraction, the ratio of the polymer organic molecules to the polar molecule is W, the polar molecule is TPBi, the polymer organic molecule is PDVT-10, and the concentration of the polymer organic molecules in the mixture is 10 mg / mL.

[0060] Step 2, prepare a substrate covered with a dielectric layer: as Figure 1 shown, the substrate 1 is a silicon wafer, the dielectric layer 2 is a SiO 2 layer covered on the substrate 1, and the thickness of the dielectric layer (SiO 2 layer) is 300 nm. The silicon wafer covered with the SiO 2 layer is purchased from Suzhou Jingsi Electronics Technology Co., Ltd.

[0061] At a power of 50 W, the dielectric layer (SiO on the substrate2 The (layer) was subjected to oxygen plasma treatment for 300 s, and SiO on the substrate 2 On the layer, an organic semiconductor solution was spin-coated with a spin coater at a rotational speed of 3000 r / s for 60 s. After spin coating, it was heated at 130 °C and kept warm for 0.5 h (annealing treatment) to evaporate chlorobenzene, cooled to room temperature, and an organic semiconductor thin film with a thickness of 80 nm was obtained on the SiO 2 layer. Evaporation was carried out at a rate of 2 Å / s through a thermal evaporation vacuum metal coater to deposit a source electrode with a thickness of 20 nm and a drain electrode with a thickness of 20 nm on the surface of the organic semiconductor thin film, obtaining a polymer organic optoelectronic transistor, wherein the source electrode is a gold electrode and the drain electrode is a gold electrode.

[0062] The W and numbers of the polymer organic optoelectronic transistors obtained by the preparation methods of Examples 1 to 4 are shown in Table 1.

[0063] Table 1

[0064]

[0065] The sizes of the substrate, dielectric layer, and organic semiconductor thin film in the polymer organic optoelectronic transistors obtained in Examples 1 to 4 are all 1 cm × 1 cm; the width-to-length ratio of the transistor channels of the polymer organic optoelectronic transistors obtained in Examples 1 to 4 is 8:1.

[0066] The structural front view of the polymer organic optoelectronic transistor is as Figure 1 shown. It can be seen from Figure 1 that the polymer organic optoelectronic transistor includes: a substrate 1, a dielectric layer 2, an organic semiconductor thin film 3, a source electrode 4, and a drain electrode 5. The organic semiconductor thin film 3 covers the dielectric layer 2 of the substrate 1, and the source electrode 4 and the drain electrode 5 are respectively located on the organic semiconductor thin film 3.

[0067] Comparative Example 1

[0068] A method for preparing a polymer organic optoelectronic transistor (number: PDVT) is basically the same as the preparation method of the polymer organic optoelectronic transistor in Example 1, except that: for the organic semiconductor solution, the organic semiconductor solution in this Comparative Example 1 is a mixture of a polymer organic molecule and chlorobenzene, wherein the polymer organic molecule is PDVT-10, and the concentration of the polymer organic molecule in the organic semiconductor solution is 10 mg / mL.

[0069] Comparative Example 2

[0070] A method for preparing a thin film of polar molecules (serial number: TPBI) is basically the same as the method for obtaining the organic semiconductor thin film in Example 1, except that: for the organic semiconductor solution, the organic semiconductor solution in this Comparative Example 2 is a mixture of polar molecules and chlorobenzene, wherein the polar molecule is TPBi, and the concentration of the polar molecule in the organic semiconductor solution is 10 mg / mL.

[0071] The organic semiconductor thin films of Example 2 and Comparative Example 1 and the polar molecule thin film of Comparative Example 2 were subjected to ultraviolet absorption tests, and the test results are as Figure 2 shown. It can be seen from Figure 2 that the doping of TPBi did not change the position and intensity of the ultraviolet absorption peak of PDVT-10. Therefore, for the organic semiconductor thin film of Example 2, the doping of TPBi did not chemically react with PDVT-10 and belongs to simple physical doping.

[0072] The organic semiconductor thin films of Examples 2 to 4 and Comparative Example 1 were subjected to X-ray diffraction tests, and the test results are as Figure 3 shown. It can be seen from Figure 3 that the doping of TPBi did not change the position and intensity of the X-ray diffraction characteristic peaks of PDVT-10, and at the same time no new characteristic peaks were generated. Therefore, for the organic semiconductor thin films of Examples 2 to 4, the doping of TPBi did not change the crystal structure of PDVT-10.

[0073] The surface morphologies of the organic semiconductor thin films of Example 2 and Comparative Example 1 were measured using an atomic force microscope, and the results are as Figure 4 shown. It can be seen from Figure 4 that compared with the organic semiconductor thin film of Comparative Example 1, the doping of TPBi did not change or damage the surface morphology of PDVT-10.

[0074] Example 5

[0075] The organic semiconductor thin films of Examples 1 to 4 and Comparative Example 1 were subjected to capacitance measurements, and their dielectric constants were calculated. The dielectric constants at a frequency of 10,000 Hz are shown in Table 2. The test results of the organic semiconductor thin films of Examples 2 to 4 and Comparative Example 1 are as Figure 5 shown. It can be seen from Figure 5 and Table 2 that with the increase in the doping content of TPBi, the capacitance and dielectric constant of the organic semiconductor thin film also increase, indicating that the doping of TPBi can increase the dielectric constant of the organic semiconductor thin film.

[0076] Table 2

[0077]

[0078] The organic semiconductor thin films of Example 2 and Comparative Example 1 were subjected to photoluminescence spectroscopy tests, and the test results are asFigure 6 As shown by Figure 6 , the doping of TPBi does not change the position of the characteristic peak of PDVT-10. This indicates that the doping of TPBi is physical doping, which is consistent with the Figure 2 analysis results. Moreover, the decrease in the response intensity of the absorbance of the organic semiconductor thin film in Example 2 can prove that the doping of TPBi enables more excitons to be separated, which helps to improve the photoelectric conversion efficiency.

[0079] The fluorescence spectra of the organic semiconductor thin films of Examples 2 to 4 and Comparative Example 1 were measured using a variable-temperature fluorescence spectrometer, and the exciton binding energy was calculated. The fluorescence spectra are as Figure 7 shown, and the exciton binding energy is shown in Table 3. As can be seen from Figure 7 and Table 3, with the increase in the doping content of TPBi, the exciton binding energy of the organic semiconductor thin film gradually decreases, verifying that the doping of TPBi can reduce the exciton binding energy of PDVT-10, showing an inverse relationship with the dielectric constant.

[0080] Table 3

[0081]

[0082] Example 6

[0083] Under the source-drain voltage (V ds ) = -60 V and in the dark, the electrical properties of the polymer organic phototransistors obtained in Examples 1 to 4 and Comparative Example 1 were tested, and the transfer curves were obtained. The transfer curves of the polymer organic phototransistors obtained in Examples 2 to 4 and Comparative Example 1 are as Figure 8 shown. As can be seen from Figure 8 , when the on-state voltage (V g ) = -60 V, in the polymer organic phototransistors obtained in Examples 2 to 4, with the increase in the doping content of TPBi, the source-drain current (I ds ) of the polymer organic phototransistors gradually decreases, but its source-drain current still remains near the source-drain current value of the polymer organic phototransistor obtained in Comparative Example 1. Among them, the source-drain current value of the polymer organic phototransistor obtained in Example 2 at the on-state voltage (V g ) = -60 V is not only higher than the source-drain current value of the polymer organic phototransistor obtained in Comparative Example 1 but also close to it, confirming that the TPBi doping ratio of the polymer organic phototransistor obtained in Example 2 is the best. Further, the average mobility and on / off ratio of the polymer organic phototransistors obtained in Examples 1 to 4 and Comparative Example 1 were statistically analyzed, as shown in Table 4. As can be seen from Table 4, the average mobilities of the polymer organic phototransistors obtained in Comparative Example 1 and Examples 1 to 4 are similar, indicating that the TPBi doping does not affect the original device performance. Among them, the on / off ratio of the polymer organic phototransistor obtained in Example 2 is 1.8×10 6, more than 10 6 , the average mobility is 0.14 cm 2 V -1 s -1 , indicating that the polymer organic optoelectronic transistor obtained in Example 2 shows better transport characteristics.

[0084] Table 4

[0085]

[0086] At V ds = -60 V, in the dark ( Figure 9 "Dark" in), or under ultraviolet light irradiation with different light intensities (light intensities are 10.9 µw / cm 2 , 19.7 µw / cm 2 , 27.3 µw / cm 2 , 40.7 µw / cm 2 and 70.6 µw / cm 2 ), the electrical properties of the polymer organic optoelectronic transistors obtained in Example 2 and Comparative Example 1 were tested, and transfer curves were obtained, as shown in Figure 9 (a) and Figure 9 (b) shown, where Figure 9 (a) represents Comparative Example 1, Figure 9 (b) represents Example 2. It can be seen from Figure 9 that compared with the dark condition, the polymer organic optoelectronic transistor obtained in Example 2 has better light response performance under different light intensities, and its light response performance can be maintained at a level similar to that of the polymer organic optoelectronic transistor obtained in Comparative Example 1.

[0087] At different on-state voltages (V g are 0 V, -20 V, -40 V, and -60 V respectively), in the dark or under ultraviolet light irradiation with a light intensity of 140 µw / cm 2 , the electrical properties of the polymer organic optoelectronic transistors obtained in Example 2 and Comparative Example 1 were tested, and output curves were obtained, as shown in Figure 10 (a) and Figure 10 (b) shown, Figure 10 (a) represents Comparative Example 1, Figure 10 (b) represents Example 2. It can be seen from Figure 10 that compared with the polymer organic optoelectronic transistor obtained in Comparative Example 1, the output curve of the polymer organic optoelectronic transistor obtained in Example 2 also maintains good light response performance, which is consistent with the results obtained from the transfer curve in Figure 9 .

[0088] Example 7

[0089] The polymer organic optoelectronic transistors obtained in Examples 1 to 4 and Comparative Example 1 were subjected to electrical performance tests at V ds = -40 V and V g = -10 V, and were irradiated with ultraviolet light (light intensity: 70.6 μW / cm 2 ) at the 5th second of the electrical performance test. The test results are shown in Table 5. The current-time curves of the polymer organic optoelectronic transistors obtained in Example 2 and Comparative Example 1 are as shown in Figure 11 . As can be seen from Figure 11 and Table 5, the polymer organic optoelectronic transistor obtained in Comparative Example 1 did not reach current saturation under ultraviolet light irradiation for more than 580 s (580,000 ms). Therefore, its light response time is more than 580 s. The polymer organic optoelectronic transistors obtained in Examples 1 to 4 can reach current saturation in a short time. Among them, the polymer organic optoelectronic transistor obtained in Example 2 has the fastest light response time of 38.27 ms, which strongly proves that the preparation method of the present invention can shorten the light response time of polymer organic optoelectronic transistors.

[0090] Table 5

[0091]

[0092] According to Table 3 and Table 4, the exciton binding energy and dielectric constant of the organic semiconductor thin film in Example 4 are the best. However, the polymer organic optoelectronic transistor obtained in Example 2 has the shortest light response time. It is speculated that the reason may be that the polymer organic optoelectronic transistor is limited by the intrinsic properties of the polymer organic semiconductor material and the fact that a large doping amount of TPBi will affect the arrangement of the polymer organic semiconductor material, resulting in the shortest light response time of the polymer organic optoelectronic transistor obtained in Example 2.

[0093] Example 8

[0094] The polymer organic optoelectronic transistors obtained in Example 2 and Comparative Example 1 were subjected to electrical performance tests at V ds = -40 V and V g = -10 V. During the electrical performance test, ten cycles of light irradiation were performed on them at the 28th second. Each cycle of light irradiation operation included: first irradiating with ultraviolet light at a light intensity of 70.6 μW / cm 2 for 5 s, and then stopping irradiation (in the dark) for 5 s. The results are as shown in Figure 12 . As can be seen from Figure 12It can be seen that for the polymer organic optoelectronic transistor obtained in Comparative Example 1, the current-time curve gradually rises under ten cycles of light illumination, verifying that it is a photonic synapse device. For the polymer organic optoelectronic transistor obtained in Example 2, due to the bias stress, the current-time curve gradually decreases under ten cycles of light illumination, verifying that it is a photosensor device. Moreover, for the polymer organic optoelectronic transistor obtained in Example 2, the photo-response time maintains good stability under ten cycles of light illumination.

[0095] In summary, through doping polar molecules (TPBi) with high dielectric properties, the present invention improves the dielectric constant of the organic semiconductor thin film, reduces the exciton binding energy of the organic semiconductor thin film, shortens the response time, and maintains good stability.

[0096] Example 9

[0097] According to Figure 9 the test results under ultraviolet light irradiation with an intensity of 70.6 μW / cm 2 in, the sensitivities (P), responsivities (R), and specific detectivities (D*) of the polymer organic optoelectronic transistors obtained in Example 2 and Comparative Example 1 are calculated respectively and plotted into corresponding curves. The calculation results of the polymer organic optoelectronic transistor obtained in Comparative Example 1 are as Figures 13 - 15 shown, and the calculation results of the polymer organic optoelectronic transistor obtained in Example 2 are as Figures 16 - 18 shown.

[0098] The calculation formulas for the sensitivity (P), responsivity (R), and specific detectivity (D*) are as follows

[0099] ;

[0100] ;

[0101] ;

[0102] Among them, I photo : Figure 9 the source-drain current under ultraviolet light illumination with an intensity of 70.6 μW / cm 2 in; I dark : Figure 9 the source-drain current in the dark in; P i : the incident light intensity (i.e., the light intensity is 70.6 μW / cm 2 ); S : the illuminated channel area (channel area: length 1000 μm × width 500 μm); e : the number of unit charges (e = 1.6 × 10 -19 C).

[0103] According to Figures 13 - 18 , the maximum values of sensitivity (P), responsivity (R) and specific detectivity (D*) of the polymer organic optoelectronic transistors obtained in Example 2 and Comparative Example 1 were respectively counted under ultraviolet light illumination with an intensity of 70.6 μW / cm 2 . The results are shown in Table 6.

[0104] Table 6

[0105]

[0106] As can be seen from Table 6, the maximum values of sensitivity and responsivity of the polymer organic optoelectronic transistors obtained in Example 2 are both greater than those of the polymer organic optoelectronic transistors obtained in Comparative Example 1, and the specific detectivity is close to that of the polymer organic optoelectronic transistors obtained in Comparative Example 1. Therefore, the polymer organic optoelectronic transistors of the present invention improve the sensitivity and responsivity and maintain a good specific detectivity.

[0107] The above is an exemplary description of the present invention. It should be noted that any simple deformation, modification or equivalent substitution that can be made by those skilled in the art without creative work falls within the protection scope of the present invention without departing from the core of the present invention.

Claims

1. A method for reducing the light response time of a polymer organic phototransistor, characterized in that: The polymer organic phototransistor comprises: a substrate, a dielectric layer, an organic semiconductor film, a source electrode and a drain electrode, wherein the dielectric layer covers the substrate, the organic semiconductor film covers the dielectric layer, and the source electrode and the drain electrode are respectively located on the organic semiconductor film, wherein the organic semiconductor film comprises: polar molecules and crystallized polymer organic molecules, wherein the polymer organic molecules are one of PDVT-10, P3HT and DPPT-TT; the polar molecules are one of TPBi, TmPyPB and TPBTP, and the ratio of the polymer organic molecules to the polar molecules is 10:(0.01-1) by mass.

2. The use according to claim 1, characterized in that The substrate is a rigid substrate or a flexible substrate.

3. The use according to claim 2, characterized in that: The rigid substrate is a silicon wafer or indium tin oxide conductive glass.

4. The use according to claim 2, characterized in that: The flexible substrate is a polydimethylsiloxane sheet or a polyimide sheet.

5. The use according to claim 1, characterized in that: The dielectric layer is a rigid dielectric layer or a flexible dielectric layer.

6. The use according to claim 5, characterized in that The rigid dielectric layer is a SiO2 layer or an Al2O3 layer.

7. The use according to claim 5, characterized in that The flexible dielectric layer is a polymethyl methacrylate layer or a polyvinyl alcohol layer.

8. The use according to claim 1, characterized in that The source is a metal electrode, a conductive polymer electrode or a carbon electrode, and the drain is a metal electrode, a conductive polymer electrode or a carbon electrode.

9. The use according to claim 8, characterized in that The metal electrode is one of a gold electrode, a silver electrode and an aluminum electrode, the conductive polymer electrode is one of a poly(3,4-ethylenedioxythiophene) poly(styrene sulfonate) electrode and a polyaniline electrode, and the carbon electrode is a carbon nanotube electrode.

10. The use according to claim 1, characterized in that The thickness of the organic semiconductor film is 5~200 nm; the thickness of the source electrode is 10~100 nm, the thickness of the drain electrode is 10~100 nm; the thickness of the dielectric layer is 5~300 nm.

11. The use according to claim 1, characterized in that The method for preparing a polymer organic phototransistor comprises the following steps: Step 1, dispersing polymer organic molecules in chlorobenzene to obtain a mixture, mixing the mixture with polar molecules to obtain an organic semiconductor solution, wherein the ratio of polymer organic molecules to polar molecules is 10:(0.01-1) by mass, the polymer organic molecules are one of PDVT-10, P3HT and DPPT-TT; the polar molecules are one of TPBi, TmPyPB and TPBTP; Step 2, prepare a substrate covered with a dielectric layer, treat the dielectric layer on the substrate with oxygen plasma, spin-coat an organic semiconductor solution on the dielectric layer of the substrate, heat and keep warm at 130-150°C for 0.5-1h, cool to room temperature, obtain an organic semiconductor film on the dielectric layer, set a source and a drain on the surface of the organic semiconductor film, and obtain a polymer organic phototransistor.

12. The use according to claim 1, characterized in that The structural formula of PDVT-10 is , number average molecular weight>50k; The structural formula of P3HT is , number average molecular weight>20k; The structural formula of the DPPT-TT is , number average molecular weight>20k.

13. The use according to claim 1, characterized in that The structural formula of TPBi is ; The structural formula of the TmPyPB is ; The structural formula of the TPBTP is .

14. The use according to claim 11, characterized in that The concentration of the polymer organic molecules in the mixture is 5-25 mg / mL.

15. The use according to claim 11, characterized in that By mass, the ratio of polymer organic molecules to polar molecules is 10:(0.05~0.4).

16. The use according to claim 11, characterized in that The power of the oxygen plasma treatment is 20~60W, and the time of the oxygen plasma treatment is 60~300s.

17. The use according to claim 11, characterized in that The spin coating speed is 1000~6000 r / s, and the spin coating time is 30~100 s.

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