First-Principles Calculations of Luminescence Spectrum Line Shapes for Defects in Semiconductors: The Example of GaN and ZnO

摘要

We present a theoretical study of broadening of defect luminescence bands dueto vibronic coupling. Numerical proof is provided for the commonly usedassumption that a multi-dimensional vibrational problem can be mapped onto aneffective one-dimensional configuration coordinate diagram. Our approach isimplemented based on density functional theory with a hybrid functional,resulting in luminescence lineshapes for important defects in GaN and ZnO thatshow unprecedented agreement with experiment. We find clear trends concerningeffective parameters that characterize luminescence bands of donor- andacceptor-type defects, thus facilitating their identification.