Defect Stability in CdTe: Formation Energies and Migration Barriers

The stability of native defects in cadmium telluride (CdTe) is analyzed based on the calculated formation energies and migration barriers. The role of defects in determining conductivity and compensation is investigated using hybrid density functional theory (DFT) calculations. Cd interstitials, though low-energy donor defects are unstable at room temperature due to their low migration barrier, which influences their ability to contribute to conductivity. They will likely move out or associate with acceptor dopants, causing passivation and reducing doping efficiency. These findings align well with experimental data, offering critical insights into optimizing CdTe-based solar cells.