Abstract
A study has been made of the characteristic emission spectrum of Er3+ implanted in zinc sulphide (melt-grown or vapour-phase-grown) and subsequently given various isochronal annealing treatments at moderate temperatures. With post-implantation annealing at increasing temperatures, it is possible to follow changes in the Er3+ line spectrum as the Er3+ ions occur first at interstitial sites (with or without perturbation by lattice defects), then at substitutional sites (again with or without defect perturbation) and finally in complex centres which can be formed as lattice defects migrate.