Overall enhancement of electrical properties of indium oxide thin-film transistors by surface doping

Abstract

Doping is a powerful tool for modulating the charge carrier density in metal oxide thin-film transistors (TFTs). However, one crucial limitation is the disruption of microstructure after doping of crystalline semiconductors, which dramatically decreases the charge carrier mobility. Here, we report on a surface doping method that utilizes organic acceptor molecules to efficiently modulate the carrier concentration without disrupting the lattice of thin indium oxide channel layers. For the first time, we achieve electron transfer from indium oxide channel to the organic layer, instead conventional strategy of organic to metal oxide, to control the intrinsic carrier concentration and enhance the electrical performance of the indium oxide TFTs. Moreover, we use a complementary tool based on spectroscopic techniques to prove the fundamental charge transfer processes between metal oxide semiconductors and organic molecular dopants. The results indicate that surface doping is a simple and effective way to improve the performance of oxide TFTs and suitable for potential applications in large-area electronics. • Indium oxide TFTs were fabricated by solution process method. • Surface doping modulates the carrier concentration of the channel layer. • The electrical performances of the devices were enhanced by surface doping.