Atomistic Insights of Orbital Engineering in a-CuO Through First-Principles Study

Abstract

First-principles calculations were performed to investigate the structural, electronic, optical, and magnetic properties of amorphous CuO (a-CuO) through orbital engineering. The representative locally distorted CuO models were validated using the melt-quench molecular dynamics approach (MD), confirming the local structural rearrangements associated with amorphization. Partial density-of-states (PDOS) analysis reveals p-type behavior with Cu-3d states dominating the valence and conduction bands, accompanied by reduced t_2g-e_g crystal-field splitting. The reduced orbital splitting enhances Cu-3d/O-2p hybridization, leading to lower exciton binding energy extracted from the optical absorption spectra. Structural disorder also increases the magnetic moment and results in a threefold enhancement in carrier mobility. Furthermore, the Au/CuO/Au device is studied under both dark and illuminated conditions, where a-CuO demonstrates a better photocurrent density of 124.63 mA/cm² at 1 V as compared to c-CuO.