A THEORETICAL-STUDY OF THE STABILITY AND ELECTRONIC-PROPERTIES OF A GAAS TE/INAS INTERFACE/

We report first-principles studies of the stability and electronic pro perties of a layer of Te atoms at an InAs/GaAs(001) interface. The cal culations are performed within the LDA approximation. Our results indi cate that the formation of half a monolayer of Te atoms is energetical ly unstable against phase segregations, indicating that the Te atoms d o not reduce the GaAs/InAs interface energy. However, a GaAs/Te(0.5)/I nAs interface can be formed on the basis of a kinetic process. The Te atoms occupying As sites have strongly covalent character, and give ri se to a half-filled band at 0.15 eV below the conduction band. The cal culated valence-band offset, with the inclusion of half a monolayer of Te atoms, presents a good agreement with experimental results.