Impurity cluster effects in high‐ and low‐doping semiconductor materials

Abstract

AbstractThe cluster‐like impurity effect in semiconductor materials as Si, GaN, GaAs, and 4HSiC for impurity concentrations spanning the metallic to the insulating regimes, i.e., from high‐ to low‐doping concentration, has been investigated at low temperature. To metallic regime a critical impurity concentration for metal–nonmetal transition is estimated from a highly correlated system by a doubly doped H‐like different impurity pairs. For insulating regime, the absorption measurements reveal low‐energy absorption peaks identified as electronic transitions in three‐donor clusters. The many‐particle correlation via a multi‐configurational self‐consistent field model is used in the calculation. © 2010 Wiley Periodicals, Inc. Int J Quantum Chem, 2010