Characterization of deep level defects in thermally annealed Fe-doped semi-insulating InP by thermally stimulated current spectroscopy

Abstract

The evaluation of deep defects in unannealed and annealed Fe-doped semi-insulating InP was studied using thermally stimulated current (TSC) and photoluminescence (PL) methods. Four TSC peaks with an ionization energy of 0.16, 0.23, and 0.42 eV, respectively, are observed clearly at an annealing temperature ranging from 400 to 700 °C. A 0.42 eV trap is associated with a deep phosphorous vacancy complex defect. 0.16 and 0.32 eV traps are related to the 917 and 888 nm PL emissions, respectively. These emissions are attributed to the deep-donor-acceptor pair transition and exciton bound to a deep level acceptor, respectively, while the 0.23 eV trap is likely to be buried in a broad TSC peak observed in a starting sample.