Enhancing perovskite TFTs performance by optimizing the interface characteristics of metal/semiconductor contact

Abstract

Organic-inorganic hybrid perovskite materials have recently attracted a great deal of research interest because of their outstanding properties. In this work, thin-film field-effect transistors (TFTs) based on organic-inorganic hybrid perovskite CH3NH3PbI3 are proposed. Molybdenum oxide (MoO3) is adopted as a buffer layer between the metal electrodes and the active layer to improve the interface performance of these devices. As a result, TFT field effect mobility increases from 1.06 to 3.88 cm2 V-1 s-1 and the subthreshold slope decreases from 3.4 V/dec to 1.6 V/dec. It is demonstrated that the improved performance of the organic-inorganic hybrid perovskite TFTs with MoO3 buffer layer can be attributed to the decrease of the hole injection barrier and the trap states density in the access region due to the doping effect. Moreover, we also suggest that the thin MoO3 film can prevent the diffusion of the metal electrode atoms into the CH3NH3PbI3 channel layer, leading to enhancement of the device performance.