Rubidium carbonate modified gold electrodes for efficient electron injection in n-type organic field-effect transistors

Abstract

We report on the performance enhancement of n-type organic field-effect transistors (OFETs) through the use of gold source and drain electrodes that are both modified with rubidium carbonate (Rb2CO3) reducing the electron injection barrier. Devices are fabricated using n-channel N, N-ditridecyl-3,4,9,10-perylenetetracarboxylicdiimide (PTCDI-C13) and a polymeric gate dielectric with various thicknesses of Rb2CO 3, and the dependence of device's electrical performance on Rb 2CO3 thickness is investigated. The device with 10Å Rb2CO3 exhibits the best performance, and its mobility is five times higher than that of the device without Rb2CO3. UV-visible, x-ray and ultraviolet photoemission spectroscopy are used to investigate the interface between Rb2CO3 and PTCDI-C 13, and we find that charge transfer from Rb2CO 3 to PTCDI-C13 occurs, resulting in the reduction of the electron charge injection barrier from the gold electrode. The charge injection mechanism and OFET performance enhancement with Rb2CO3 are discussed in detail. © 2014 IOP Publishing Ltd.