Hybrid functional calculations of a Te antisite in bulk CdTe
The detection of gamma-rays is an important issue in a cast array ofindustries. CdTe is a semiconductor used for gamma-ray detectors whichcan operate at high temperatures. Density functional theory calculationsof the electronic structure within the Perdew-Burke-Ernzerhof exchange-correlation functional underestimate the bandgap of CdTe: the calculatedbandgap within PBE is less than half the experimental value. The useof a hybrid functional approach to exchange and correlation describes thebandgap correctly. The goal of this project was to nd out if PBE calcu-lations give an adequate description of defects in CdTe by comparing it tohybrid functional calculations. We show that PBE is adequate in describ-ing Te antisite defects in CdTe if a correction to the bandgap is applied.The defect level for both PBE and hybrid functional was calculated to be0.24 eV above the valance band.
AT THIS PAGE YOU CAN DOWNLOAD THE WHOLE ESSAY. (follow the link to the next page)