# US 2019/0378979 A1 · Method of manufacturing organic semiconductor thin film using bar-coating process and method of fabricating flexible organic semiconductor transistor comprising the same > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2019/0378979 A1 - Document ID: US20190378979A1 - Status: Published application - Kind: A1 - Application number: 16/189,897 - Filed: 2018-11-13 - Published: 2019-12-12 - Earliest claimed: 2018-06-08 - Assignees: Center for Advanced Soft Electronics; Postech Academy-Industry Foundation - Applicants: Center for Advanced Soft Electronics; Postech Academy-Industry Foundation - Inventors: Kilwon CHO; Seon Baek LEE; Boseok KANG - Web page: https://patentgrep.com/patent/US20190378979A1 ## CPC - H10K 71/12: using liquid deposition, e.g. spin coating - H10K 71/13: using printing techniques, e.g. ink-jet printing or screen printing - H10K 10/464: {Lateral top-gate IGFETs comprising only a single gate} - H10K 10/484: {characterised by the channel regions} - H10K 85/623: {containing five rings, e.g. pentacene} - H10K 85/631: {Amine compounds having at least two aryl rest on at least one amine-nitrogen atom, e.g. triphenylamine} - H10K 85/6576: {comprising only sulfur in the heteroaromatic polycondensed ring system, e.g. benzothiophene} - H10K 77/111: {Flexible substrates} - Y02E 10/549: Organic PV cells - Y02P 70/50: Manufacturing or production processes characterised by the final manufactured product - H10K: ORGANIC ELECTRIC SOLID-STATE DEVICES - Y02E: REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION - Y02P: CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS ## Abstract Disclosed is a method of manufacturing an organic semiconductor thin film, including preparing semiconductor ink containing a solvent, a low-molecular-weight organic semiconductor and a high-molecular-weight organic semiconductor and forming an organic semiconductor thin film vertically phase-separated by applying the semiconductor ink on a substrate through a bar-coating process using a bar. In the bar-coating process of the invention, the semiconductor ink blend is used, and the gap between the substrate and the bar is adjusted, thus controlling vertical phase separation. Also, the speed of the bar, the gap of which is adjusted, is regulated, thus controlling crystal growth, whereby the uniformity of the thin film is improved and thus a high-quality organic semiconductor crystalline thin film having a large area can be manufactured in a continuous process. Also, a flexible organic semiconductor transistor, having high stability and high charge mobility, can be provided using the organic semiconductor thin film. ## Claims ### Claim 1 A method of manufacturing an organic semiconductor thin film, comprising: (a) preparing semiconductor ink containing a solvent, a low-molecular-weight organic semiconductor and a high-molecular-weight organic semiconductor; and (b) forming an organic semiconductor thin film that is vertically phase-separated by applying the semiconductor ink on a substrate through a bar-coating process using a bar. ### Claim 2 (depends on 1) The method of claim 1, wherein, in step (b), a size of a gap between the bar and the substrate is adjusted to thus control vertical phase separation of the organic semiconductor thin film. ### Claim 3 (depends on 1) The method of claim 1, wherein, in step (b), a movement speed of the bar during the bar-coating process is adjusted to thus control a crystal shape, a crystal size and/or a crystal growth rate of the organic semiconductor thin film. ### Claim 4 (depends on 1) The method of claim 1, wherein step (b) comprises: (b-1) performing coating at a movement speed of the bar ranging from 0.1 to 2 mm/sec (v1) during the bar-coating process; and (b-2) stopping movement of the bar after step (b-1) or performing coating at a movement speed of the bar ranging from 0.01 to 0.05 mm/sec. ### Claim 5 (depends on 4) The method of claim 4, wherein steps (b-1) and (b-2) are sequentially or continuously repeated. ### Claim 6 (depends on 1) The method of claim 1, wherein the organic semiconductor thin film comprises: a high-molecular-weight organic semiconductor layer formed on the substrate and configured to contain a high-molecular-weight organic semiconductor; and a low-molecular-weight organic semiconductor layer formed on the high-molecular-weight organic semiconductor layer and configured to contain a low-molecular-weight organic semiconductor, the low-molecular-weight organic semiconductor layer being crystalline. ### Claim 7 (depends on 2) The method of claim 2, wherein a thickness, a flow rate and a phase separation of the semiconductor ink are controlled depending on the size of the gap. ### Claim 8 (depends on 2) The method of claim 2, wherein the size of the gap is 0.01 to 10 μm. ### Claim 9 (depends on 3) The method of claim 3, wherein the speed of the bar during the bar-coating process is 0.05 to 2 mm/sec. ### Claim 10 (depends on 1) The method of claim 1, wherein, in step (b), vertical phase separation and crystal growth occur while the solvent of the semiconductor ink evaporates. ### Claim 11 (depends on 10) The method of claim 10, wherein a crystal growth rate is controlled by adjusting an evaporation rate of the solvent. ### Claim 12 (depends on 1) The method of claim 1, wherein crystals of the low-molecular-weight organic semiconductor are arranged in a direction of movement of the bar. ### Claim 13 (depends on 1) The method of claim 1, wherein vertical phase separation is controlled using a difference between surface energy of the low-molecular-weight organic semiconductor and surface energy of the high-molecular-weight organic semiconductor, the substrate is hydrophilic, a first organic semiconductor layer containing an organic semiconductor having relatively high surface energy among the high-molecular-weight organic semiconductor and the low-molecular-weight organic semiconductor is formed on the substrate, and a second organic semiconductor layer containing an organic semiconductor having relatively low surface energy is formed on the first organic semiconductor layer, or the substrate is hydrophobic, a second organic semiconductor layer containing an organic semiconductor having relatively low surface energy among the high-molecular-weight organic semiconductor and the low-molecular-weight organic semiconductor is formed on the substrate, and a first organic semiconductor layer containing an organic semiconductor having relatively high surface energy is formed on the second organic semiconductor layer. ### Claim 14 (depends on 1) The method of claim 1, wherein the low-molecular-weight organic semiconductor has a molecular weight of 50 to 1,000. ### Claim 15 (depends on 1) The method of claim 1, wherein the high-molecular-weight organic semiconductor has a molecular weight of 2,000 to 1,000,000. ### Claim 16 (depends on 1) The method of claim 1, wherein the low-molecular-weight organic semiconductor is a compound represented by Structural Formula 1 below: in Structural Formula 1, X1 and X2 are the same as or different from each other, and are each independently an oxygen (O), sulfur (S), nitrogen (N), phosphorus (P) or selenium (Se) atom, and R1 and R2 are the same as or different from each other, and are each independently a hydrogen atom, a C1 to C30 linear or branched alkyl group, or a C6 to C30 aryl group. ### Claim 17 (depends on 1) The method of claim 1, wherein the low-molecular-weight organic semiconductor includes at least one selected from among a pentacene derivative compound and a TES-ADT (5,11-bis(triethylsilylethynyl)anthradithiophene) derivative compound. ### Claim 18 (depends on 1) The method of claim 1, wherein the high-molecular-weight organic semiconductor is a compound represented by Structural Formula 2 below: in Structural Formula 2, R1 to R3 are the same as or different from each other, and are each independently a hydrogen atom, a C1 to C30 linear or branched alkyl group, or a C6 to C30 aryl group, R4 and R5 are the same as or different from each other, and are each independently a hydrogen atom, a C1 to C30 linear or branched alkyl group, or a C6 to C30 aryl group, and n is any one integer of 1 to 50. ### Claim 19 (depends on 1) The method of claim 1, wherein the high-molecular-weight organic semiconductor includes at least one selected from among poly(triaryl amine) (PTAA), indacenodithiophene-co-benzothiadiazole (IDT-BT), and poly(9,9-dioctylfluorene-alt-bithiophene) (F8T2). ### Claim 20 A method of fabricating an organic transistor, comprising: (a) preparing semiconductor ink containing a solvent, a low-molecular-weight organic semiconductor and a high-molecular-weight organic semiconductor; (b) providing a substrate and forming source and drain electrodes on the substrate; (c) forming an organic semiconductor thin film that is vertically phase-separated by applying the semiconductor ink on the substrate having the source and drain electrodes formed thereon through a bar-coating process using a bar; (d) forming an insulating layer on the organic semiconductor thin film; and (e) forming a gate electrode on the insulating layer.