Atomistic investigation of the electronic structure, thermal properties and conduction defects in Ge-rich GexSe1−x materials for selector applications

Abstract

We investigate the electronic structure and defects of GexSe1−x materials at the atomic level, using full-layer-thickness (5nm) amorphous models. In Ge-rich GexSe1−x, the nature of the mobility gap defects is mostly related to miscoordinated Ge. The population/localization of mobility-gap states changes solely under the effect of electric field. Strong covalent bonds introduced by N doping in the material increase its thermal conductivity and crystallization temperature beyond 600C. C/N dopants are found to add/remove mobility-gap states in the doped systems. Our investigation sets guidelines for material design in view of improved electro-thermal device performance.