High-mobility, air stable bottom-contact n-channel thin film transistors based on N,N′-ditridecyl perylene diimide

Abstract

Bottom-gate bottom-contact (BGBC) organic thin film transistors (OTFTs) based on N,N′-ditridecyl perylene diimide exhibit electron mobility as high as 3.54 cm2 V−1 s−1 in nitrogen, higher than that (1 cm2 V−1 s−1) of bottom-gate top-contact devices. The better performance of BGBC configuration in N2 is attributed to lower contact resistance, which is further reduced by thermal annealing. After thermally annealing the BGBC OTFTs at 180 °C, electron mobility as high as 3.5 cm2 V−1 s−1, current on/off ratio of 106 and threshold voltage of 9 V are achieved in air, and the mobility retains above 1 cm2 V−1 s−1 after storage for two months in air. Thermal treatment enhanced crystalline grains, reduced grain boundaries, and suppressed the adsorption of H2O and O2, leading to excellent performance in air.