Ab initio study of antisite defective layered Ge_2Sb_2Te_5

摘要

By means of ab initio calculations, we have investigated the antisite defects in layered Ge_2Sb_2Te_5 (GST). Our results show that both Te_(Sb) and Sb_(Te) antisite defective GST alloys are energetically favorable and mechanically stable. Furthermore, the presence of antisite defects results in the decrease in band gaps and hence the increase in the electrical conductivity, while shows slight effect on chemical bonding characters. Based on the present results, increased electrical conductivity and decreased thermal conductivity are expected by introducing antisite defects in GST related layered materials.