Identification of donor species in high-purity GaAs using optically pumped submillimeter lasers

Abstract
An optically pumped NH3 laser has been used in conjunction with careful doping experiments in high‐purity GaAs to determine the ionization energy of isolated tin donors. The energy obtained is 5.820 meV, which corresponds to a central‐cell correction of 0.081 meV. This technique for impurity analysis is estimated to be sensitive to donor concentrations of less than 1011 cm−3.