Diluted magnetic semiconductors with narrow band gaps

TL;DR

This paper introduces a method to create diluted magnetic semiconductors with narrow band gaps using computational techniques, demonstrating potential for high Curie temperatures in Mn-doped compounds.

Contribution

It proposes a novel approach to realize narrow-gap DMS with both p- and n-type carriers, supported by theoretical predictions of higher Curie temperatures in new materials.

Findings

Mn-doped BaZn2As2 has a band gap of 0.2 eV.

Predicted Curie temperature of Mn-doped BaZn2Sb2 exceeds that of BaZn2As2.

Theoretical methods successfully identify promising DMS materials.

Abstract

We propose a method to realize diluted magnetic semiconductors (DMS) with p- and n-type carriers by choosing host semiconductors with a narrow band gap. By employing a combination of the density function theory and quantum Monte Carlo simulation, we demonstrate such semiconductors using Mn-doped BaZn2As2, which has a band gap of 0.2 eV. In addition, we found a new non-toxic DMS Mn-doped BaZn2Sb2, of which the Curie temperature Tc is predicted to be higher than that of Mn-doped BaZn2As2, the Tc of which was up to 230 K in the recent experiment.