Arsenic incorporation in MBE grown Hg1−xCdxTe

Study focuses on developing an understanding of the microscopic behavior of As incorporation during MBE growth. In particular, the question of whether As incorporates as individual As atoms, as As2 dimers, or as As4 tetramers is addressed for MBE growth with an As4 source. A quasi- thermodynamical model is employed to describe the MCT growth and As incorporation, with parameters fitted to an extensive database of samples. The best fits for growth temperatures between 175 and 185 C are obtained for As incorporation as As4 or possibly as As4 clusters, with lower probabilities for As2 and individual As atoms. Based on these results, authors investigate the relaxed atomic configurations of As4 and As2 in bulk HgTe by ab initio total energy calculations. The calculations are performed in the pseudopotential density- functional framework within the local density approximation, employing supercells with periodic boundary conditions. 11 refs.