Rare-earth defects in wide band-gap semiconductors

Rare-earth (RE) defects are of great interest for luminescence and quantum information science. Yet defect physics of RE-doped wide band-gap semiconductors is currently not well understood. First-principles defect calculations based on a hybrid DFT/Hartree-Fock approach can provide a detailed understanding of the atomic and electronic structure, energetics, and optical properties of RE dopants in solid compounds [1]. In this talk, we discuss (i) the interaction between the RE dopants in the lanthanide series and the GaN host and its implications on intra-f and band-to-defect luminescence, and (ii) RE-related defects in CaS and SrAl₂O₄ and their role in persistent luminescence mechanisms. [1] K. Hoang, Phys. Rev. Mater. 5, 034601 (2021).