Studies of the substitutional site of Co2+ in AgGaS2 crystal from EPR data

The EPR zero-field splitting D and g factors g(parallel to), Delta g ( = g( parallel to) - g(inverted perpendicular)) for Co2+ ions at Ag+ and Ga3+ sit es of sulphur-annealed AgGaS2 crystal were calculated from the high-order p erturbation formulas based on the two spin-orbit coupling parameter model. The calculated results show that Co2+ replace Ag+ site in the AgCaS2 crysta l. This point is contrary to that obtained from the absorption spectrum and Raman spectroscopy studies for Co2+ in as-grown AgGaS2 crystal. It appears that Co2+ can replace Ag+ or Ga3+ site in AgGaS2 ternary semiconductor, de pending on the technology of material preparation. (C) 1998 Published by El sevier Science Ltd.