Improving performance of OFET by tuning occurrence of charge transport based on pentacene interaction with SAM functionalized contacts

Abstract

Optimized pentacene thin film transistors have been achieved by two technological self-assembled monolayers (SAM) treatments, with surface modification of 3-octadecyltrichlorosilane (OTS) monolayer on SiO2 dielectric layer and 2,3,4,5,6-pentafluorobenzenethiol (PFBT) monolayer on gold source/drain electrodes, respectively. Higher mobility and on/off ratio with 0.36 cm2 V−1 s−1 and >106 are consistently investigated for films deposited on PFBT compared to on OTS, which could be explained by the different occurrence charge transport near the semiconductor/dielectric and semiconductor/electrodes interfaces. It can be further confirmed by XPS and electrical property measurements. In the end, a high mobility increased up to 0.68 cm2 V−1 s−1 was obtained by cumulative treatments of the two SAM. In particular, the improving performance of the organic thin films transistor devices through tuning the charge transport with SAM layers highlighting the utility of surface modulations and controlling of charge transport of interfaces in nanoscale materials.