This work was supported by a Korea Science and Engineering Foundation (KOSEF) grant funded by the Korean government (MEST) (No. R0A-2007-000-20053-0). Supporting Information is available online from Wiley InterScience or from the author.
Highly Sensitive, Photocontrolled, Organic Thin-Film Transistors Using Soluble Star-shaped Conjugated Molecules†
Article first published online: 22 SEP 2008
Copyright © 2008 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim
Advanced Functional Materials
Volume 18, Issue 19, pages 2905–2912, October 9, 2008
How to Cite
Cho, M. Y., Kim, S. J., Han, Y. D., Park, D. H., Kim, K. H., Choi, D. H. and Joo, J. (2008), Highly Sensitive, Photocontrolled, Organic Thin-Film Transistors Using Soluble Star-shaped Conjugated Molecules. Adv. Funct. Mater., 18: 2905–2912. doi: 10.1002/adfm.200800358
- Issue published online: 6 OCT 2008
- Article first published online: 22 SEP 2008
- Manuscript Received: 13 MAR 2008
- Korean government (MEST). Grant Number: R0A-2007-000-20053-0
- conjugated molecules;
- organic electronics;
- thin films
The highly photosensitive characteristics of organic thin-film transistors (OTFTs) made using soluble star-shaped oligothiophenes with four-armed π-conjugation paths, 4(HPBT)-benzene and 4(HP3T)-benzene molecules having a relatively high quantum yield, are reported. 4(HPBT)-benzene-based organic phototransistors (OPTs) exhibited high photosensitivity (∼2500–4300 A W−1) even with low optical powers (∼6.8–30 µW cm−2) at zero gate bias. The measured photosensitivity of the devices was much higher than that of inorganic single-crystal Si-based phototransistors, as well as that of other OPTs reported earlier. With the highly photosensitive characteristics of the 4(HPBT)-benzene-based OPTs, a high ratio of the on and off current switching of ∼4 × 104 with low optical power and low gate bias was observed. The slow relaxation of the photoinduced charges and charge-trapping phenomena at the interface could lead to a reproducible memory operation for 4(HPBT)-benzene-based OPTs.