Gamma-ray irradiated organic thin film transistors based on perfluoropentacene with polyimide gate insulator

Abstract

N-channel field effect transistors with a Si/polyimide(PI)/perfluoropentacene/Au structure were fabricated, and irradiated wby gamma-ray ith a Co 60 source. The changes of the drain current I D vs. source/drain voltage V SD(I D - V SD) characteristics were measured after every 200 Gray in silicon (Gy Si) irradiations up to the total dose of 1200 Gy Si. The drain current I D graduai ly increased up to the total dose of 1200 Gy Si. The threshold voltage V th decreased up to 400 Gy Si, and gradually recovered above 600 Gy Si. The mobility μ was almost unchanged up to 1200 Gy Si. Those behaviors were explained by accumulation of positive trapped charge within the gate insulator PI near the interface. Evidence for the accumulation of interface traps was hardly observed. © 2012CPST.