Polycrystalline films of material which had been doped to Cu concentrations of between 1020 and 1021/cm3 were studied by using optical absorption and transmittance techniques, scanning electron microscopy, X-ray diffraction and ellipsometry. It was found that the so-called Cu+ off-center effect was present in the films, as demonstrated by means of optical and thermally stimulated depolarization current measurements.

L.Oliveira, C.M.G.S.Cruz, M.A.P.Silva, M.Siu-Li: Radiation Effects and Defects in Solids, 1995, 134, 357-60