Excitation spectra of ZnS phosphors part III: Low temperature effects

Processes determining excitation spectra are discussed. The spectra are interpreted by the absorption spectrum and the combined action of nonradiative recombinations on the crystal surface and in the bulk. Low temperature excitation spectra can be explained by the decrease of carrier diffusion length. The surface recombination velocity of microcrystalline samples varies between 3 × 104−107 cm/sec at 300°K.