Solution-processed ternary p-type CuCrO2 semiconductor thin films and their application in transistors

Abstract

In this study, transparent p-type CuCr_xO_y semiconductor thin films were fabricated using spin coating and integrated as channel layers in thin-film transistors (TFTs). The structural, morphological components, and optical properties of CuCr_xO_y thin films, together with device performance, were systematically investigated. The phase conversion from a mixture of CuCr₂O₄ and CuO to pure CuCrO₂ was achieved when the annealing temperature (T_a) was higher than 700 °C. The electrical performance of the CuCr_xO_y TFTs on SiO₂ dielectric is improved with increasing T_a from 500 °C to 800 °C. The optimized CuCrO₂ TFT exhibits an on/off current ratio of ∼10⁵ and a hole mobility of 0.59 cm² V⁻¹ s⁻¹, which is much better than those previous works on solution-processed binary Cu_xO TFTs. To our best knowledge, this work demonstrates the ternary p-type CuCrO₂ TFTs fabricated via a low-cost solution process for the first time, which represents an important advancement towards the development of all-oxide, low-cost p–n junctions and CMOS logic circuits.