T_c-Enhanced Codoping Method for GaAs-based Dilute Magnetic Semiconductors

TL;DR

This paper proposes a new codoping method for GaAs-based dilute magnetic semiconductors that significantly increases the Curie temperature by enhancing Mn solubility and modifying electronic structure, potentially achieving room-temperature ferromagnetism.

Contribution

The study introduces a T_c-enhanced codoping technique using N or C to improve Mn solubility and electronic properties in GaAs-based semiconductors, a novel approach in the field.

Findings

Mn solubility is increased with N or C codoping.

Curie temperature exceeds room temperature at x>0.06.

Impurity band broadening enhances magnetic properties.

Abstract

Based on ab initio calculations of Ga_{1-x}Mn_xN_yAs_{1-y} and Ga_{1-x}Mn_xC_yAs_{1-y}, we propose a new codoping method to enhance the Curie temperature T_c of diluted magnetic semiconductors. The solubility of Mn can be increased up to high concentration by the codoping of N or C to reduce the lattice and volume expansion caused by Mn doping. It is found that the impurity band of the majority spin is strongly broadened and pushed up into the higher energy region due to the strong p-d hybridization caused by the codoping, and the T_c becomes higher than the room temperature at x>0.06.