Polymer binder assisted, solution processed cyanophenyl functionalized diketopyrrolopyrrole microwire for n-channel field-effect transistors

Kyoseung Sim, Akshaya K. Palai, Gergely Tarsoly, Hanah Na and Seungmoon Pyo

Synthetic Metals 2019 250 152-160. DOI: 10.1016/j.synthmet.2019.03.005


A cyanophenyl functionalized diketopyrrolopyrrole molecular semiconductor, DPP-PhCN, is used as an n-channel active material for organic field-effect transistors (FETs) with a polymer gate dielectric. Two types of DPP-PhCN active layer are prepared for the formation of the FET devices; 1) thin-film formed through a thermal vacuum deposition at different substrate temperatures and 2) microwire (single and multiple), prepared through a polymer binder assisted solution process. Both types of devices show electron dominant charge transport behavior. The device based on the polymer assisted solution processed microwire exhibit higher performance than the device with a thin-film. The highest electron mobility of 0.23 cm2/Vs in ambient condition is achieved from a device with only one microwire of DPP-PhCN, and is 30 times higher than that of the device with DPP-PhCN thin-film (0.008 cm2/Vs).