Pressure-induced structural and electronic evolution of cadmium oxide (CdO): a first-principles

This study investigates the structural and electronic properties of cadmium oxide (CdO) in its rock-salt (B1) phase under high pressure, employing first-principles density functional theory (DFT) calculations. The FP-LAPW method, coupled with the TB-mBJ potential, was used to obtain accurate results. Our findings indicate that CdO remains stable in the B1 structure under ambient conditions and undergoes a phase transition to the (B2) structure at approximately 87 GPa. Analysis of the electronic structure reveals that CdO behaves as an indirect band gap semiconductor. The indirect band gap increases from 2.10 eV at ambient pressure to 2.35 eV at 80 GPa, while the direct Γ–Γ gap increases from 3.09 eV to 5.06 eV, demonstrating a clear pressure dependence of the electronic structure. By accurately modeling these pressure-induced transitions, this work provides useful insights for understanding CdO's performance in advanced electronic and optoelectronic devices.