Electronic structure of noble metal impurities in semiconductors: Cu in GaP

TL;DR

This paper develops a Green function-based numerical method to analyze the electronic structure of transition metal impurities in semiconductors, specifically applying it to Cu in GaP, revealing unfilled 3d shells relevant for magnetic properties.

Contribution

A novel Green function technique for calculating impurity electronic structures in semiconductors, combining LDA+U and linearized augmented plane wave methods.

Findings

Cu impurity has an unfilled 3d shell in GaP

Method compares favorably with supercell LDA results

Results suggest magnetic ordering potential in dilute alloys

Abstract

A numerical method for calculation of the electronic structure of transition metal impurities in semiconductors based on the Green function technique is developed. The electronic structure of 3d impurity is calculated within the LDA+U version of density functional method, whereas the host electron Green function is calculated by using the linearized augmented plane wave expansion. The method is applied to the Cu impurity in GaP. The results of calculations are compared with those obtained within the supercell LDA procedure. It is shown that in the Green function approach Cu impurity has an unfilled 3d shell. This result paves a way to explanation of the magnetic order in dilute Ga_{1-x}Cu_xP alloys.