Deep impurity levels in epitaxial PbS films

Abstract

Compensation of sulfur vacancies in hot wall grown epitaxial films produces materials with very low carrier concentrations, p 77 k ∼3 × 10 22/m 3). At these lower concentrations, an impurity center is found, tentatively identified with the dominant Si impurity, and which produces a deep electron trap and acceptor level 0.079 eV above the valence band. At low temperatures, the lifetime rises to 65 milliseconds indicating minority carrier trapping.