Organic thin film transistor

• US 8,445,894 B2
• Filed: 02/18/2009
• Issued: 05/21/2013
• Est. Priority Date: 02/16/2006
• Status: Expired due to Fees

• Current Assignee: Idemitsu Kosan Company Limited, Kyushu University
• Original Assignee: Idemitsu Kosan Company Limited, Kyushu University
• Inventors: Nakamura, Hiroaki, Saitou, Masatoshi, Tsutsui, Tetsuo, Yasuda, Takeshi
• Primary Examiner(s): Wagner, Jenny L
• Assistant Examiner(s): TORNOW, MARK W
• Application Number:
  US12/388,119
• Publication Number:
  US 20090159878A1
• Time in Patent Office: 1,553 Days
• Field of Search: 257/40, 257/E51.001, 257/E51.027, 257/E51.028, 257/E51.031
• US Class Current: 257/40
• CPC Class Codes: C07C 15/52 containing a group with formula
• CPC Class Codes: C07C 22/08 containing fluorine
• CPC Class Codes: C07C 25/24 Halogenated aromatic hydrocarbons with unsaturated side chains
• CPC Class Codes: C07C 43/215 having unsaturation outside the six-membered aromatic rings
• CPC Class Codes: H10K 10/464 Lateral top-gate IGFETs comprising only a single gate
• CPC Class Codes: H10K 10/466 Lateral bottom-gate IGFETs comprising only a single gate
• CPC Class Codes: H10K 10/471 the gate dielectric comprising only organic materials
• CPC Class Codes: H10K 10/472 the gate dielectric comprising only inorganic materials
• CPC Class Codes: H10K 10/84 Ohmic electrodes, e.g. source or drain electrodes
• CPC Class Codes: H10K 71/621 Providing a shape to conductive layers, e.g. patterning or selective deposition
• CPC Class Codes: H10K 85/114 Poly-phenylenevinylene; Derivatives thereof
• CPC Class Codes: H10K 85/60 Organic compounds having low molecular weight H10K85/10 - H10K85/50 take precedence
• CPC Class Codes: H10K 85/626 containing more than one polycyclic condensed aromatic rings, e.g. bis-anthracene
• CPC Class Codes: H10K 85/655 comprising only sulfur as heteroatom
• CPC Class Codes: H10K 85/657 Polycyclic condensed heteroaromatic hydrocarbons
• CPC Class Codes: H10K 85/6572 comprising only nitrogen in the heteroaromatic polycondensed ring system, e.g. phenanthroline or carbazole
• CPC Class Codes: H10K 85/6576 comprising only sulfur in the heteroaromatic polycondensed ring system, e.g. benzothiophene
• CPC Class Codes: H10K 85/731 Liquid crystalline materials

Abstract

A thin film transistor comprising at least three terminals consisting of a gate electrode, a source electrode and a drain electrode; an insulator layer and an organic semiconductor layer on a substrate, which controls its electric current flowing between the source and the drain by applying a electric voltage across the gate electrode, wherein the organic semiconductor layer comprises a styryl derivative having a styryl structure expressed by C₆H₅—CH═CH—C₆H₅, or a distyryl structure expressed by C₆H₅—CH═CH—C₆H₅—CH═CH—C₆H₅ each without molecular weight distribution. The transistor has a fast response speed (driving speed), and further, achieves a large On/Off ratio getting an enhanced performance as a transistor.

Claims

1. A thin film transistor comprising at least three terminals consisting of a gate electrode, a source electrode and a drain electrode;

an insulator layer and an organic semiconductor layer on a substrate, which controls an electric current flowing between the source and the drain by applying an electric voltage across the gate electrode, wherein the organic semiconductor layer comprises a styryl compound represented by formula (a);

2. The organic thin film transistor according to claim 1, wherein R₁, R₂, R₄ to R₁₅ and R₁₇ to R₂₂ are all hydrogen atoms;

R₃ or R₁₆ is an alkyl group having 1 to 3 atoms.

3. The organic thin film transistor according to claim 1, wherein double bonds of a conjugated main chain of the styryl compound represented by the general formula (a) are disposed in trans position to each other.

4. The organic thin film transistor according to claim 1, wherein the styryl compound is represented by a following general formula (a′

);