We report the fabrication and characterization of solution-processed organic bilayer field effect transistors with a middle-contact configuration. P3HT and PCBM were chosen for a hole and electron transporting material, respectively. The P3HT:PCBM bilayer FET with a middle contact structure showed only p-type behavior with a hole mobility (μ_h) of ~ 10^-3 cm² V^-1 s^-1, which is a different result compared to the conventional top-contact ambipolar device. Electron injection was enabled by using a thin CPE layer beneath the PCBM layer. The thickness of the CPE layer is critical for achieving balanced hole and electron mobilities and provides an important variable for consideration in future optimization studies. More detailed mechanisms on the role of CPE layer and the middle-contact structure are currently under investigation.

Date Published: 11 September 2013
PDF: 9 pages
Proc. SPIE 8811, Physical Chemistry of Interfaces and Nanomaterials XII, 88110S (11 September 2013); doi: 10.1117/12.2023745

Published in SPIE Proceedings Vol. 8811:
Physical Chemistry of Interfaces and Nanomaterials XII
Natalie Banerji; Carlos Silva, Editor(s)