Electronic and transformation properties of a metastable defect introduced inn-type GaAs by α-particle irradiation

We report the electronic and transformation characteristics of an {α}-particle irradiation-induced defect in n-type GaAs with metastable properties, E{α}3, as determined by deep-level transient spectroscopy. The E{α}3, with an energy level at Ec-0.37 eV, captures electrons by multiphonon emission. It can be removed by hole injection and reintroduced during a first-order transformation under zero-bias annealing (activation energy {Δ}E=0.40 eV), or during reverse-bias annealing ({Δ}E=0.53 eV). It is suggested that E{α}3 is related to a Si-impurity complex in n-type GaAs. Owing to its concentration and position in the band gap, E{α}3 can significantly contribute to particle irradiation-induced carrier removal---due to its metastable properties the extent of the carrier removal may depend on bias and injection conditions.