The production and structure of the P-P3anti-site defect in electron-irradiated n-type GaP

Abstract
Samples of n-type GaP doped with either (a) sulphur or (b) silicon to concentrations of about 1018 atoms/cm3 have been compared using EPR and IR measurements following a series of small doses of 2 MeV electron irradiation at room temperature. The EPR spectrum due to the (P-P3) antisite defect is produced up to a similar strength in both materials. The measurements suggest that it is unlikely that the defect involves an impurity. The authors speculate that the (P-P3) centre may be a gallium vacancy distorted to give (Vp-PGa) or a trigonal (VP-PGa-Gai) complex produced by a knock-on process.