Improvement of hole injection characteristics in wet-processed organic field-effect transistor based on oxidation of silver electrode surface

Abstract

Source–drain electrodes for organic field-effect transistors (OFETs) were fabricated with Ag nanoink on a Si wafer with a 300 nm thick oxide layer using the repellent patterning method, and a depth-profile analysis of the composition and physical properties of the electrode surface was performed once the electrode was oxidized by UV–ozone irradiation. Additionally, OFETs with a wet-processed electrode and 9,10-diphenylanthracene layer were fabricated, and their electrical characteristics were measured. The chemical composition of the Ag electrode surface changed to silver oxide (Ag2O or AgO) due to the longer oxidation treatment time, and the work function value increased. In the OFET with the electrode oxidized for 600 s, increased drain current ∣I D∣ was observed around a gate voltage of 0 V. Furthermore, good OFET characteristics were obtained [maximum ∣I D∣ = 326.2 μA, mobility μ = 0.91 cm2V −1·s−1], which were similar to those of the OFETs manufactured using a dry process.