Method for enhancing stability of aggregation state of organic semiconductor film

Abstract

A method for enhancing aggregation state stability of organic semiconductor (OSC) films includes constructing the OSC film; introducing uniform and discontinuous nanoparticles on a surface of the film or an inside of the film. Electrical properties of the OSC film are not influenced by introducing the nanoparticles. Grain boundary, dislocation, stacking fault, and surface of the film are pinned by the nanoparticles, increasing potential barrier of the aggregation state evolution of the film, and thus enhancing the stability of the aggregation state and greatly improving maximum working temperature and storage lifetime of organic field-effect transistors. Under room temperature storage, morphology of the OSC film introduced with the nanoparticles is difficult to change, so that the stability of electrical properties of organic transistor components prepared from the film is ensured in a high-temperature and atmospheric working environment.

Claims

1. A method for enhancing stability of aggregation state of an organic semiconductor film, comprising: constructing the organic semiconductor film on a surface of an insulating substrate; and introducing nanoparticles into one of a surface of the constructed organic semiconductor film and an inside of the constructed organic semiconductor film, wherein the nanoparticles are uniform and discontinuous, and a volume fraction of the nanoparticles is between 0.1% and 3% accounting for a volume of the organic semiconductor film.

2. The method according to claim 1, wherein the method further comprises: preparing a gate conductive electrode.

3. The method according to claim 1, wherein the organic semiconductor film is a polycrystalline film.

4. The method according to claim 3, wherein the organic semiconductor film is one of an organic small-molecule semiconductor and an organic polymer semiconductor.

5. The method according to claim 1, wherein a diameter of each of the nanoparticles is between 0.01 nanometer (nm) and 100 nm.

6. The method according to claim 5, wherein each of the nanoparticles is one of a metal conductor particle, an organic semiconductor particle, an inorganic semiconductor particle and an insulator particle.

7. The method according to claim 1, wherein the method further comprises: preparing a source electrode and a drain electrode by patterning.

Description

BRIEF DESCRIPTION OF DRAWINGS

(1) In order to explain technical schemes of embodiments of the disclosure more clearly, the following will briefly introduce attached drawings required in the embodiments. Apparently, the attached drawings in following descriptions are only some of the embodiments of the disclosure. For those skilled in the related art, other drawings can be obtained according to the attached drawings without creative effort.

(2) FIG. 1 is a schematic diagram of enhancing stability of an aggregation state of an organic semiconductor film by introducing nanoparticles according to a method of the disclosure.

(3) FIGS. 2A-2D show schematic diagrams of organic field-effect transistors according to embodiments of the disclosure; FIG. 2A is a schematic diagram of a bottom-gate top-contact organic field-effect transistor; FIG. 2B is a schematic diagram of a bottom-gate bottom-contact organic field-effect transistor; FIG. 2C is a schematic diagram of a top-gate top-contact organic field-effect transistor; FIG. 2D is a schematic diagram of a top-gate bottom-contact organic field-effect transistor.

(4) FIGS. 3A-3F show schematic diagrams of morphologies of the organic semiconductor film before and after annealing with a scale of 2 micrometers (μm) according to embodiments of the disclosure; FIG. 3A is a schematic diagram of the morphology of DNTT film at room temperature; FIG. 3B is a schematic diagram of the morphology of the DNTT film after annealing at 210° C. for 30 minutes; FIG. 3C is a schematic diagram of the morphology of DNTT film doped with Au nanoparticles at room temperature; FIG. 3D is a schematic diagram of the morphology of the DNTT film doped with Au nanoparticles after annealing at 210° C. for 30 minutes; FIG. 3E is a schematic diagram of the morphology of DNTT film bulk phase-doped with Au nanoparticles at room temperature; FIG. 3F is a schematic diagram of the morphology of the DNTT film bulk phase-doped with Au nanoparticles after annealing at 210° C. for 30 minutes.

(5) FIG. 4 shows a comparison diagram of normalized motilities of pure DNTT, 1.5% volume fraction of Au NP-DNTT and 2.0% volume fraction of Au NP-DNTT respectively at different temperatures according to the embodiments of the disclosure.

(6) FIG. 5 shows a schematic diagram of a mobility of the organic semiconductor field-effect transistor prepared from pristine DNTT film and a mobility of the organic semiconductor field-effect transistor prepared from the embodiment 1 placed at room temperature for different times according to the embodiments of the disclosure.

(7) FIGS. 6A-6D show schematic diagrams of morphologies of P3HT film before and after annealing with a scale of 15 μm according to the embodiments of the disclosure; FIG. 6A is a schematic diagram of the morphology of the P3HT film at room temperature; FIG. 6B is a schematic diagram of the morphology of the P3HT film after annealing at 300° C. for 1 hour; FIG. 6C is a schematic diagram of the morphology of P3HT film doped with Au nanoparticles at room temperature; FIG. 6D is a schematic diagram of the morphology of the P3HT film doped with Au nanoparticles after annealing at 300° C. for 1 hour.

(8) FIGS. 7A-7D show schematic diagrams of morphologies of the organic semiconductor film before and after annealing with a scale of 15 μm according to embodiments of the disclosure; FIG. 7A is a schematic diagram of the morphology of DNTT film at room temperature; FIG. 7B is a schematic diagram of the morphology of the DNTT film after annealing at 210° C. for 30 minutes; FIG. 7C is a schematic diagram of the morphology of DNTT film bulk phase-doped with Au nanoparticles at room temperature; FIG. 7D is a schematic diagram of the morphology of the DNTT film bulk phase-doped with Au nanoparticles after annealing at 210° C. for 30 minutes.

(9) FIG. 8 is a statistical diagram of thermal stability temperature comparison between pristine phase films and Au nanoparticles reinforced dispersion films of different semiconductors.

(10) FIGS. 9A-9B show schematic diagrams of morphologies of DNTT organic semiconductor film doped with different nanoparticles before and after annealing with a scale of 15 μm according to embodiments of the disclosure; FIG. 9A is a schematic diagram of the morphology of the DNTT organic semiconductor film doped with different nanoparticles at room temperature; FIG. 9B is a schematic diagram of the morphology of the DNTT organic semiconductor film doped with different nanoparticles after annealing at 220° C. for 30 minutes.

(11) FIGS. 10A-10D are transmission electron micrographs of DNTT organic semiconductor film doped with nanoparticles of different volume fractions with a scale of 20 μm according to embodiments of the disclosure; FIG. 10A is the transmission electron micrograph of DNTT organic semiconductor film doped with nanoparticles of 0.1% volume fraction; FIG. 10B is the transmission electron micrograph of DNTT organic semiconductor film doped with nanoparticles of 0.5% volume fraction; FIG. 10C is the transmission electron micrograph of DNTT organic semiconductor film doped with nanoparticles of 1.5% volume fraction; FIG. 10D is the transmission electron micrograph of DNTT organic semiconductor film doped with nanoparticles of 3% volume fraction.

DETAILED DESCRIPTION OF EMBODIMENTS

(12) Various illustrated embodiments of the disclosure are described in detail as follows, and the detailed descriptions cannot be considered as a limitation to the disclosure, but should be understood as the more detailed descriptions of some certain aspects, features and technical schemes of the disclosure.

(13) It should be understood that the terms described in the disclosure are intended to describe the illustrated embodiments only and are not intended to limit the disclosure. In addition, a range of values in the disclosure should be understood that each intermediate value between the upper value and the lower value of the range is also disclosed. Each smaller range between the value or the intermediate value within the range and any other value or intermediate value within the range is also included in the disclosure. The upper value and the lower value of these smaller ranges can be independently included or excluded from the range.

(14) Unless otherwise indicated, all of technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the related art. Although the disclosure describes only the illustrated method and materials, any method and materials similar or equivalent to those described herein should also be used in the implementation or testing of the disclosure. All of the literatures referred to in the specification of the disclosure are incorporated by reference for the purpose of disclosing and describing the method and/or materials associated with the literatures. In the event of conflict with any incorporated literatures, the contents of the specification of the disclosure shall prevail.

(15) Without departing from the scope or spirit of the disclosure, various improvements and variations are made to the illustrated embodiments of the disclosure, as will be obvious to those skilled in the related art. Other embodiments derived from the specification of the disclosure are obvious to those skilled. The specification and embodiments of the disclosure are exemplary only.

(16) The terms “contains”, “includes”, “has”, “contains”, etc. used herein are tolerant terms, namely that these terms mean including but not limited to.

(17) The purchasing source of materials in the embodiments is as follows.

(18) Organic Semiconductor Molecules:

(19) DNTT with a structural formula expressed as follows:

(20) ##STR00001##

(21) Purification of the DNTT: 99%.

(22) Source: Shanghai Daran Chemical Co.

(23) DPA with a structural formula expressed as follows:

(24) ##STR00002##

(25) Purification of the DPA: 99%.

(26) Source: Shanghai Daran Chemical Co.

(27) PTCDA with a structural formula expressed as follows:

(28) ##STR00003##

(29) Purification of the PTCDA: 99%.

(30) Source: Shanghai Daran Chemical Co.

(31) PTCPI-CH.sub.2C.sub.3H.sub.7 with a structural formula expressed as follows:

(32) ##STR00004##

(33) Purification of the PTCPI-CH.sub.2C.sub.3H.sub.7: 99%.

(34) Source: Shanghai Daran Chemical Co.

(35) Pentacene with a structural formula expressed as follows:

(36) ##STR00005##

(37) Purification of the pentacene: 99%.

(38) Source: Shanghai Daran Chemical Co.

(39) N1100 with a structural formula expressed as follows:

(40) ##STR00006##

(41) Purification of the N1100: 99%.

(42) N1200 with a structural formula expressed as follows:

(43) ##STR00007##

(44) Polymer Semiconductor:

(45) P3HT with a structural formula expressed as follows:

(46) ##STR00008##
with an average molecular weight being between 40,000 and 100,000; and source: Sigma Aldrich (Shanghai) Trading Co.

(47) N2200 with a structural formula expressed as follows:

(48) ##STR00009##
with an average molecular weight being≥30,000.

(49) PBTTT-C14 with a molecular formula as follows:

(50) ##STR00010##
with an average molecular weight being≥20,000.

(51) Nanoparticles:

(52) Metal:

(53) Gold (Au) with a purification of 99.999%;

(54) Silver (Ag) with a purification of 99.999%;

(55) Aluminum (Al) with a purification of 99.999%;

(56) Chromium (Cr) with a purification of 99.999%.

(57) Semiconductor:

(58) Fullerene (C.sub.60) with a purification of 99%; source: Shanghai Daran Chemical Co.

(59) Insulator:

(60) Molybdenum trioxide (MoO.sub.3) with a purification of 99.998%; source: Alfa Aesar (China) Chemical Co.

(61) The schematic diagram of the method for enhancing the stability of the aggregation state of the organic semiconductor film of the disclosure with introducing nanoparticles is shown in FIG. 1.

(62) The disclosure use organic field-effect transistors prepared by the organic semiconductor films with introducing nanoparticles as the illustrated embodiments to quantitatively characterize the stability of electrical properties of the transistors. The other electronic components constructed with the organic semiconductor layer such as organic light-emitting diode (OLED) prepared by the organic semiconductor films with introducing nanoparticles can also bear the higher working temperature and extend the storage life.

Embodiment 1

(63) (1) A silicon wafer containing 300 nanometers (nm) silicon dioxide and 500 micrometers (μm) heavily doped silicon is selected; a size of the silicon wafer is 1 centimeter (cm)×1 cm; the 500 μm heavily doped silicon is used as a gate electrode; octadecyltrichlorosilane (OTS) is modified on the 300 nm silicon dioxide by a vacuum gas phase method at 120° C. for 1 hour to obtain a silicon dioxide insulating layer modified with the OTS.

(64) (2) A metallic source electrode and a metallic drain electrode are metallized on a surface of the silicon dioxide insulating layer modified with the OTS by thermal evaporation; a rate of the thermal evaporation is 0.1 Å/s and thicknesses of the electrodes are 20 nm.

(65) (3) A DNTT film is thermally vaporized on the insulating layer containing the source electrode and the drain electrode; a thickness of the DNTT film is 20 nm and a rate of the thermal evaporation is 0.05 Å/s.

(66) (4) Au nanoparticles are thermally vaporized on a surface of the DNTT film with a rate of 0.05 Å/s for 60 seconds. The DNTT film is doped Au with a volume fraction of 1.5%. During introducing the nanoparticles, a substrate needs to be rotated at a rotation rate of 5 rpm to obtain a bottom-gate bottom-contact organic field-effect transistor (Au-DNTT organic field-effect transistor, as shown in FIG. 2B).

Embodiment 2

(67) (1) A silicon wafer containing 300 nm silicon dioxide and 500 μm heavily doped silicon is selected; a size of the silicon wafer is 1 cm×1 cm; the 500 μm heavily doped silicon is used as a gate electrode; OTS is modified on the 300 nm silicon dioxide by a vacuum gas phase method at 120° C. for 1 hour to obtain a silicon dioxide insulating layer modified with the OTS.

(68) (2) A metallic source electrode and a metallic drain electrode are metallized on a surface of the silicon dioxide insulating layer modified with the OTS by thermal evaporation; a rate of the thermal evaporation is 0.1 Å/s and thicknesses of the electrodes are 20 nm; a DNTT film is thermally vaporized on a substrate with a thickness of 30 nm, while the DNTT film is doped Au with a volume fraction of 2% in a rate of 0.05 Å/s for 120 seconds. During introducing the nanoparticles, the substrate needs to be rotated at a rotation rate of 5 rpm for uniformly bulk phase-doping the film with Au nanoparticles.

(69) (3) A surface of the DNTT film is thermally vaporized the source electrode and the drain electrode to obtain an organic field-effect transistor; thicknesses of the electrodes are 30 nm, and a rate of the thermal evaporation is 0.1 Å/s.

(70) In order to verify morphological stability of the organic semiconductor film, the morphology of the DNTT organic field-effect transistor doped with Au nanoparticles (also referred to as the Au-DNTT organic field-effect transistor) is observed by an atomic force microscopy before and after annealing at 210° C. for 30 minutes (as shown in FIGS. 3C-3D). The organic film is a channel part of the prepared transistor. And it is found that the morphology does not change significantly under a condition of annealing at 210° C. for 30 minutes, which means that the aggregation state of the organic film is able to withstand a higher temperature. The electrical properties of the Au-DNTT organic field-effect transistor are further tested, and maximum working temperatures of the Au-DNTT organic field-effect transistors that are doped with the Au nanoparticles in different volume fractions are determined by testing a mobility of the transistors at different temperatures (as shown in FIG. 4). The testing results show that the electrical properties of the organic semiconductor transistors without introducing nanoparticles decrease as the testing temperature increases, while the Au-DNTT transistors doped with the Au nanoparticles in different volume fractions are stable in the high temperature and their electrical properties at the temperatures less than 210° C. are stable, which broadens the working temperature range of the organic transistors. The transistors with introducing nanoparticles and those without introducing nanoparticles are tracked and tested for up to 6 years. The electrical properties are measured to quantitatively characterize their failure extent. The results show that the properties of the organic semiconductor field-effect transistors without introducing nanoparticles decrease gradually at room temperature, and almost completely fail after 6 years, while the electrical properties of the organic semiconductor field-effect transistors with introducing nanoparticles remain stable after 6 years of storage at room temperature (as shown in FIG. 5). The above means that it is difficult to change the morphology of the organic semiconductor film with introducing nanoparticles under normal temperature storage, which ensures the stability of the electrical properties of the organic field-effect transistors prepared by the organic semiconductor film at high temperatures and in the actual environment.

(71) The nanoparticles can be introduced not only to the surface of the organic semiconductor film, but also the bulk phase of the film to stabilize the structure of the film. With specific reference to embodiment 3, the preparation method of the nanoparticles and the organic semiconductor film includes, but is not limited to, thermal evaporation method, atomic layer deposition method, electron beam evaporation method, magnetron sputtering method, hydrogen arc plasma method, laser evaporation method, galvanizing process method, spin-coating method, sol-gel process method, pulling into synchronism method or dripping method.

Embodiment 3

(72) (1) A silicon wafer containing 300 nm silicon dioxide and 500 μm heavily doped silicon is selected; a size of the silicon wafer is 1 cm×1 cm; the 500 μm heavily doped silicon is used as a gate electrode; OTS is modified on the 300 nm silicon dioxide by a vacuum gas phase method at 120° C. for 1 hour to obtain a silicon dioxide insulating layer modified with the OTS.

(73) (2) A metallic source electrode and a metallic drain electrode are metallized on a surface of the silicon dioxide insulating layer modified with the OTS by thermal evaporation; a rate of the thermal evaporation is 0.1 Å/s and thicknesses of the electrodes are 20 nm; a DNTT film is thermally vaporized on a substrate with a thickness of 30 nm, while the DNTT film is doped Au with a volume fraction of 1.5% in a rate of 0.05 Å/s for 60 seconds. During introducing the nanoparticles, the substrate needs to be rotated at a rotation rate of 5 rpm for uniformly bulk phase-doping the film with the Au nanoparticles.

(74) (3) A surface of the DNTT film is thermally vaporized the source electrode and the drain electrode to obtain an organic field-effect transistor; thicknesses of the electrodes are 30 nm and a rate of the thermal evaporation is 0.1 Å/s.

(75) In order to verify morphological stability of the DNTT organic semiconductor film bulk phase-doped with Au nanoparticles, the morphology of the DNTT organic field-effect transistor bulk phase-doped with Au nanoparticles (also referred to as bulk phase Au-DNTT) is observed by the atomic force microscopy before and after annealing at 210° C. for 30 minutes (as shown in FIGS. 7C-7D). And it is found that the morphology does not change significantly under the condition of annealing at 210° C. for 30 minutes, which means that the morphology of the organic film is able to withstand a higher temperature. A comparison embodiment is embodiment 5 (as shown in FIGS. 3A-3B).

(76) In order to verify morphological stability of the organic semiconductor film, the local morphology of the DNTT organic field-effect transistor is observed by the atomic force microscopy before and after annealing at 210° C. for 30 minutes (as shown in FIGS. 3E-3F). And it is found that the morphology changes significantly under the condition of annealing at 210° C. for 30 minutes, and the continuity of the semiconductor film decreases under the high temperature. In addition, the morphology of the film before and after annealing is further characterized by using a three-dimensional confocal microscopy, and it is found that the film is continuous and homogeneous before and after annealing (as shown in FIGS. 7C-7D). And the structure of aggregation state is very stable, and the semiconductor film with introducing nanoparticles has good thermal stability.

(77) The method of the disclosure can be used not only for the preparation of organic small-molecule semiconductor films, but also for the preparation of organic polymer semiconductor films, which has a significant effect of enhancing the stability of the aggregation state.

Embodiment 4

(78) (1) A silicon wafer containing 300 nm silicon dioxide and 500 μm heavily doped silicon is selected; a size of the silicon wafer is 1 cm×1 cm; the 500 μm heavily doped silicon is used as a gate electrode; OTS is modified on the 300 nm silicon dioxide by a vacuum gas phase method at 120° C. for 1 hour to obtain a silicon dioxide insulating layer modified with the OTS.

(79) (2) A metallic source electrode and a metallic drain electrode are metallized on a surface of the silicon dioxide insulating layer modified with the OTS by thermal evaporation; a rate of the thermal evaporation is 0.1 Å/s and thicknesses of the electrodes are 20 nm.

(80) (3) The insulating layer containing the source electrode and the drain electrode is spin-coated with a polymer of 3-hexylthiophene (P3HT) film; a concentration of the P3HT film is 8 milligrams per millliter (mg/mL), a solvent is toluene; 30 μL P3HT is dropped on the silicon dioxide, a rotating rate of the substrate is 3000 rpm and a rotating time is 50 seconds; and the substrate is heated at 100° C. for 5 minutes to make the excess solvent evaporate to obtain a P3HT polymer film.

(81) (4) A surface of the P3HT polymer film is thermally vaporized at a rate of 0.05 Å/s for 60 seconds; the P3HT polymer film is doped Au with a volume fraction of 1.5%. During introducing the nanoparticles, the substrate needs to be rotated at a rotation rate of 5 rpm to obtain a bottom-gate bottom-contact organic field-effect transistor.

(82) In order to verify morphological stability of the P3HT polymer semiconductor, the morphology of the P3HT organic field-effect transistor doped with Au nanoparticles (also referred to as an Au-P3HT organic field-effect transistor) is observed by the atomic force microscopy before and after annealing at 300° C. for 1 h (as shown in FIGS. 6C-6D). And it is found that the morphology does not change significantly under the condition of annealing at 300° C. for 1 h, which means that the morphology is able to withstand a higher temperature.

(83) To prove that the method of the disclosure has excellent results, the embodiments 5-6 are set up for comparison, as follows.

Embodiment 5

(84) (1) A silicon wafer containing 300 nm silicon dioxide and 500 μm heavily doped silicon is selected; a size of the silicon wafer is 1 cm×1 cm; the 500 μm heavily doped silicon is used as a gate electrode; OTS is modified on the 300 nm silicon dioxide by a vacuum gas phase method at 120° C. for 1 hour to obtain a silicon dioxide insulating layer modified with the OTS.

(85) (2) A metallic source electrode and a metallic drain electrode are metallized on a surface of the silicon dioxide insulating layer modified with the OTS by thermal evaporation; a rate of the thermal evaporation is 0.1 Å/s and thicknesses of the electrodes are 20 nm.

(86) (3) A DNTT film is thermally vaporized on the insulating layer containing the source electrode and the drain electrode; a thickness of the DNTT film is 30 nm and a rate of the thermal evaporation is 0.05 Å/s.

(87) In order to verify morphological stability of the organic semiconductor, the local morphology of the DNTT organic field-effect transistor is observed by the atomic force microscopy at 210° C. before annealing and after annealing for 30 minutes (as shown in FIGS. 3A-3B). And it is found that the morphology changes significantly under the condition of annealing at 210° C. for 30 minutes and a continuity of the semiconductor film decreases under the high temperature. In addition, the three-dimensional confocal microscope is used to further characterize the morphology of the film after annealing, and it is found that the film has a continuous and uniform morphology compared with that before annealing (as shown in FIG. 7A), and the overall film is no longer continuous (as shown in FIG. 7B), which means the aggregation state is unstable. The electrical properties of the DNTT organic field-effect transistor are further tested, and the maximum working temperature of the DNTT organic field-effect transistors is determined by testing the mobility of the transistor at different temperatures, and a high temperature lifetime is characterized by testing lifetime at 150° C. And it is found that under the above two kinds of testing conditions, the mobility shows that the electrical properties are unstable at the high temperatures. According to a ratio between drift values of the threshold voltage and switching ratio change of the embodiment 4 and the embodiment 1, the embodiment 4 is manifested in the drift of threshold voltage and the decrease of switching ratio, while the embodiment 1 shows a stable threshold voltage and switching ratio. FIG. 4 shows the normalized mobility comparison between the embodiment 1 and the embodiment 4. It can be found that the mobility of semiconductor film (in the embodiment 1) with introducing nanoparticles is very stable, while that of the embodiment 4 is decreasing.

Embodiment 6

(88) (1) A silicon wafer containing 300 nm silicon dioxide and 500 μm heavily doped silicon is selected; a size of the silicon wafer is 1 cm×1 cm; the 500 μm heavily doped silicon is used as a gate electrode; OTS is modified on the 300 nm silicon dioxide by a vacuum gas phase method at 120° C. for 1 hour to obtain a silicon dioxide insulating layer modified with the OTS.

(89) (2) A metallic source electrode and a metallic drain electrode are metallized on a surface of the silicon dioxide insulating layer modified with the OTS by thermal evaporation; a rate of the thermal evaporation is 0.1 Å/s and thicknesses of the electrodes are 20 nm.

(90) (3) The insulating layer containing the source electrode and the drain electrode is spin-coated with a P3HT film; a concentration of the P3HT film is 8 mg/mL, a solvent is toluene; 30 μL P3HT is dropped on the silicon dioxide, a rotating rate of the substrate is 3000 rpm and a rotating time is 50 seconds; and the substrate is heated at 100° C. for 5 minutes to make the excess solvent evaporate to obtain a bottom-gate bottom-contact organic field-effect transistor prepared from the P3HT polymer film.

(91) In order to verify morphological stability of the P3HT polymer semiconductor, the morphology of the P3HT organic field-effect transistor doped with Au nanoparticles (also referred to as an Au-P3HT organic field-effect transistor) is observed by the atomic force microscopy before and after annealing at 300° C. for 1 h (as shown in FIG. 6A-6B). And it is found that the organic semiconductor film undergoes dewetting after annealing at 300° C. for 1 h, which is manifested in that the film is no longer uniform, the substrate coverage is reduced, and the continuity is reduced, indicating that the morphology is easy to change at high temperatures.

(92) The embodiments 1-4 of the disclosure shows the organic semiconductor films with high working temperature and long life and the corresponding organic filed effect transistors. And the embodiments 5-6 are for comparison with the embodiments 1-4 of the disclosure. The embodiments 1-4 keep the morphology and electrical properties of the organic field-effect transistors stable under high temperature and continuous thermal stress by introducing the nanoparticles. The morphology and electrical properties of the organic field-effect transistors in the embodiments 5-6 are unstable under the high temperature and continuous thermal stress.

(93) The Au nanoparticles in the DNTT films are replaced with other dispersive phase nanoparticles (such as Ag, Al, Cr, Cho, MoO.sub.3) to verify pervasiveness of the dispersive phase nanoparticles, which is achieved by respectively preparing Ag nanoparticles (NP)-DNTT films, Al NP-DNTT films, Cr NP-DNTT films, C.sub.60 NP-DNTT films, and MoO.sub.3 NP-DNTT films. In addition, pristine DNTT films are prepared to be regarded as the comparison. FIG. 8 shows a statistical diagram of thermal stability temperature comparison between pristine phased films of different semiconductors and Au nanoparticle reinforced dispersion films. The morphological changes of the films before and after annealing at 220° C. are observed by the three-dimensional confocal microscopy (as shown in FIG. 9A-9B). FIG. 9A shows the morphologies at room temperature before annealing, and it can be found that the films are all uniform and continuous. FIG. 9B shows the morphologies after annealing at 220° C., and it is found that the continuity of other films with dispersed nanoparticles is better than that of the pure DNTT film, compared with that the pristine DNTT film is no longer continuous, which proves that the method of the disclosure switching to other dispersion particles is still applicable.

(94) A transmission electron micrograph of the DNTT organic semiconductor film doped with Au nanoparticles in different volume fractions according to the same method as the embodiment 1 are shown in FIGS. 10A-10D, where FIG. 10A shows a volume fraction of 0.1% with a scale of 20 nm; FIG. 10B shows a volume fraction of 0.5% with a scale of 20 nm; FIG. 10C shows a volume fraction of 1.5% with a scale of 20 nm; FIG. 10D shows a volume fraction of 3% with a scale of 20 nm. From FIGS. 10A-10D, it can be seen that different volume fractions will make diameters of the nanoparticles slightly different, but they are still within a scale of nanometer, uniform and discontinuous, and there is no significant difference in working effect. When the volume fraction of the nanoparticles is not less than 3%, the nanoparticles attract each other due to interactions, thus leading to clustering and the uniformity decreases to some extent, so the uniformity of the nanoparticles in the organic films can be enhanced by controlling the volume fraction of the nanoparticles, which also ensures that the nanoparticles will not affect the electrical properties of the organic semiconductor film.

(95) The above described embodiments are only the illustrated embodiments of the disclosure, not a limitation of the scope of the disclosure. Without departing from the spirit of the design of the disclosure, all kinds of deformations and improvements made to the technical schemes of the disclosure by those skilled in the related art shall fall within the scope of the protection determined by the disclosure.