Experimental and computational insights into CuS–Mg composites for high-performance p-type transparent conducting materials

Abstract

Achieving fully transparent electronic devices requires improving p-type transparent conducting materials (TCMs) to match their n-type counterparts. This study explores novel p-type TCMs using high-throughput screening via an automatic spray pyrolysis system. The performance of conducting wide bandgap chalcogenide based on CuS can be improved by incorporating various cations, with Mg emerging as the most promising candidate. The optimized CuS–Mg films exhibited superior transparency and conductivity, comparable to state-of-the-art p-type TCMs. Density functional theory (DFT) calculations linked the inverse correlation between transparency and conductivity to changes in Cu 3d and S 3p orbital coupling with varying Mg content. The best CuS–Mg composition demonstrated high hole concentration (5 × 10²¹ cm⁻³), low sheet resistance (266 Ω □⁻¹), and high transparency (∼75%). The transmittance increased by ∼30% compared with pristine CuS. The successful application of a p-CuS–Mg/n-CdS heterojunction as a semi-transparent photodiode highlights its potential for smart displays and window-integrated electronics. This study demonstrates the value of combining experimental and theoretical methods for accelerated material discovery.