Impurity states in the narrow band-gap semiconductor n-type InSb

Abstract

We investigate impurity pair and triad formations in the narrow band-gap semiconductor n-doped InSb. It is found that in the region of the band-gap energy, Eg = 0.23 eV, at 0 K, the effects of such clusters play a relevant role in the optical properties around and below the ionization energy of an isolated impurity (i.e., Ei = 0.64 meV). The transition for the uncompensated system is obtained as the concentration of impurities exceeds Nc = 4.7 × 1013 cm−3.