Multiplet structures of transition-metal deep impurities in GaAs

Abstract

The multiplet structures of substitutional 3d transition-metal (TM) impurities Ti to Ni in GaAs have been calculated by the first-principles cluster method which connects the calculated results of the one-electron energy levels by the LDA approach on the cluster consisting of 59 atoms with the ligand-field theory of Sugano, Tanabe and Kamimura (1970). The present theory explains fairly well experimental results on the low-lying multiplets of various TM impurities in GaAs and also reproduces qualitatively the observed chemical trend seen in the ionisation energies of TM impurity acceptors.