CU+ high doping effects in KCl and KBr films

Abstract

Highly Cu + doped KCl and KBr polycrystalline films were investigated in the range of 10 20 -10 21 cm -3 Cu + concentration. Several techniques were used to obtain the optical and structural properties, as optical absorption and transmittance, electronic microscopy (SEM), X-ray diffraction and ellipsometry. The Cu + off-center effect is still present in the films, as determined by optical and thermally stimulated depolarization current measurements (TSDC). The films were obtained by thermal evaporation, and the corresponding doping Cu-halide is introduced in the same evaporating crucible. Samples with diverse concentrations, ranging from nominal 1 to 10% mole, were prepared. The increase of Cu + concentration results in an improved cyrstallinity of the grains, with higher density and a better transmittance of the film above 350 nm. Optical application as UV filter device can be considered.