AVS 52nd International Symposium
    Electronic Materials and Processing Friday Sessions
       Session EM-FrM

Paper EM-FrM4
Effect of Poly (3-hexylthiophene) Film Thickness on Organic Thin Film Transistor Properties

Friday, November 4, 2005, 9:20 am, Room 309

Session: Organic Electronic Devices
Presenter: H. Jia, University of Texas at Dallas
Authors: H. Jia, University of Texas at Dallas
S Gowrisanker, University of Texas at Dallas
G.K. Pant, University of Texas at Dallas
R.M. Wallace, University of Texas at Dallas
B.E. Gnade, University of Texas at Dallas
Correspondent: Click to Email
We present the effect of poly (3-hexylthiophene) thickness on the performance of OTFTs. When the poly (3-hexylthiophen) film thickness varies from 3.8nm to 23.8nm, the drain current and the saturation mobility increase with the thickness because of the higher channel conductance. In contrast, the on/off ratio decreases with P3HT film thickness, primarily because of the higher off current. Gate leakage also becomes higher when the film thickness increases, also contributing to a lower on/off ratio. The threshold voltage is more sensitive to dielectric surface treatment than to the thickness of P3HT film thickness. The mobility increases and then saturates with gate voltage. For devices from thick P3HT films, increasing gate voltage further after saturation decreases the mobility. Short channel effects are observed for channel lengths of @<=@ 5 µm. We also present the channel length dependence of threshold voltage and mobility. The drive current, on/off ratio, and mobility of P3HT devices should be optimized based on the specific application. @Footnote Text@@footnote 1@ Jiyoul Lee, Kibum Kim, Jae Hoon Kim, Seongil Im, Duk-Young Jung, Appl. Phys. Lett. 82, 4169 (2003) @footnote 2@ Satoshi Hoshino, Toshihide Kamata, and Kiyoshi Yase, J. Appl. Phys. 6028 (2002) @footnote 3@ R. Schroeder, L. A. Majewski, and M. Grell, Appl. Phys. Lett. 83, 3201 (2003) @footnote 4@ Manabu Kiguchi, Manabu Nakayama, Kohei Fujiwara, Keiji Ueno, Toshihiro Shimada and Koichiro Saiki, Jpn. J. Appl. Phys. 42, L1408(2003)