Properties of vacancy defects in GaAs single crystals

摘要: The electrical properties of GaAs single crystals were measured after annealing at various elevated temperatures in controlled atmospheres. Two types defects introduced as the result annealing: (i) donors having a high concentration near surface and (ii) acceptors lower but extending further into crystal. As overpressure dependencies indicate that are vacancies Ga since their respective concentrations proportional to iPAs4−1/4 iPAs4+1/4. entropy enthalpy changes for vacancy formation reactions evaluated, based on experimental data thermodynamic analysis. diffusion coefficients follow relations D (VGa) =2.1×10−3 exp(−2.1/kT) (VAs) =7.9×103 exp(−4.0/kT). Both form nonradiative centers determined from photoluminescence experiments.