1. Department of Electrical and Computer Engineering, Inter‐university Semiconductor Research Center, Seoul National University, 1 Gwanak‐ro, Gwanak‐gu, Seoul 151‐742, Korea;2. Advanced Materials Division, Korea Research Institute of Chemical Technology, Daejeon 305‐600, Korea;3. Department of Materials Science and Engineering, The University of Seoul, Dongdaemun‐gu, Seoul 130‐743, Korea
Abstract:
This Letter reports the novel use of poly(9‐vinylcarbazole) (PVK) as a dielectric interfacial layer for n‐type organic field‐effect transistors (n‐OFETs). With PVK, both the air stability and electron mobility of N,N′‐ditridecylperylene‐3,4,9,10‐tetracarboxylic diimide (PTCDI‐C13)‐based OFETs were improved. Among the PVKs with different weight‐average molecular weight (Mw), PVK with high Mw showed good performance. The high glass transition temperature of PVK enabled thermal post annealing of the active layer, which resulted in a high electron mobility of 0.61 cm2/Vs. This mobility was maintained at 90% and 59% after 4 days and 105 days in air, respectively. The PVK interfacial layer reduced the trapped charges in the PTCDI‐C13‐based n‐OFET for air‐exposure and caused a decrease in the threshold voltage shift.
