Diluted magnetic semiconductors with narrow band gaps

Gu, B.; 前川 禎通

Gu, B.; Maekawa, Sadamichi

The diluted magnetic semiconductors (DMSs) have received considerable attention owing to potential applications based on the use of both charge and spin degrees of freedom in electronic devices. Historically, (Ga,Mn)As has received the most attention in DMSs, and so far the highest Curie temperature in (Ga,Mn)As has been = 190 K in the experiment. The substitution of divalent Mn atoms into trivalent Ga sites introduces hole carriers; thus, (Ga,Mn)As is a -type DMS. Here, we propose a method to realize DMSs with - and -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 BaZnAs, which has a band gap of 0.2 eV. In addition, we found a nontoxic DMS Mn-doped BaZnSb, of which the Curie temperature is predicted to be higher than that of Mn-doped BaZnAs, the of which was up to 230 K in a recent experiment.