Luminescence properties of SrS:Ce thin films

In this contribution, luminescence properties of SrS:Ce,Cl thin films prepared by reactive evaporation are presented. Basic properties of Ce3+ in SrS thin films are evaluated in low doped SrS thin films corresponding to the case that isolated luminescent centers are incorporated. Moreover, the impact of high doping on the luminescence properties is evaluated. High doping leads to changed luminescent conditions due to interaction of the luminescent centers. In addition, influences of defects created at high doping levels are observed. The interactions cause a red-shift of the Ce3+ luminescence spectra and are responsible for non-radiant losses. Presumably, the defects are Sr vacancies assuring the charge-compensation in SrS:Ce,Cl thin films. Furthermore, the solubility of Ce3+ in our SrS thin films is characterized. It turns out that the solubility of Ce3+ is reduced compared to charge-compensated powders.