Field-effect transistors based on organic single crystals grown by an improved vapor phase method

• Published in: Organic electronics Vol. 10; no. 7; pp. 1241 - 1247
• Main Authors: Yamao, Takeshi, Juri, Keiichiro, Kamoi, Akira, Hotta, Shu
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 01.11.2009; Elsevier
• Subjects: Applied sciences; Electronics; Exact sciences and technology; Organic field-effect transistor; Organic single crystal; Semiconductor electronics. Microelectronics. Optoelectronics. Solid state devices; Transistors; Vapor phase method; Vapor phase method; 85.30.Tv; 73.61.Ph; 81.10.Bk; Organic field-effect transistor; Organic single crystal; 72.80.Le; Self-assembled layer; Crystal growth; Performance evaluation; Crystallographic direction; Thiophene; Oligomer; Single crystal; Field effect transistor; Semiconductor device; Thermodynamic model; Benzene; Top contact configuration; Organic electronics; Crack
• ISSN: 1566-1199; 1878-5530
• DOI: 10.1016/j.orgel.2009.06.017

High-quality organic single crystals are produced directly onto the substrates using an improved vapor phase method. Unlike the conventional vapor phase methods, the present method is characterized by forming a large-sized crystal to which semiconductor devices can readily be made. The relevant method requires small space of only a ∼10-cm cube in which a couple of plates are put in close proximity. The crystal growth is carried out nearly at the thermodynamic equilibrium within the narrow space surrounded with the two plates. Thin single crystals of several hundreds of micrometers in size are grown on one of those plates. For the organic materials to be crystallized, we have chosen 1,4-bis(5-phenylthiophen-2-yl)benzene (AC5) and 5,5 ⁗ -diphenyl-2,2′:5′,2″:5″,2‴:5‴,2 ⁗ -quinquethiophene (P5T) from among thiophene/phenylene co-oligomers. The resulting crystals are well-defined polygons, each side reflecting the specific crystallographic orientation. In particular, those grown on self-assembled monolayers are exceedingly flat and free from cracks. We have directly fabricated top-contact field-effect transistors on these crystals. The devices exhibit the excellent performance and keep it both in air and in vacuum for a maximum of a hundred days.