The effect of plastic deformation and heat treatment upon absorption (10.6) and low-temperature luminescence was investigated. The intensities of the 2.12eV emission and of the 10.6 absorption both increased with deformation, and both of them decreased after annealing to 620K and slowly re-cooling to room temperature. It was suggested that the absorption and luminescence were associated with cation vacancies, and that their concentrations were affected by the mechanical and thermal treatments.

L.Nagli, S.Shalem, A.Shmilevich, A.Katzir, N.Kristianpoller: Materials Science Forum, 1997, 239-241, 163-6