Structural and optical characterization of undoped and indium – doped CdS films grown by pulsed laser deposition

Undoped CdSe and CdSe:Zn thin films have been grown on silicon substrate by using pulsed laser deposition technique. The electrical, structural and optical properties have been investigated. The films grow crystalline and highly oriented. Electrical measurements show that they are n-type doped. The reflectivity and photoluminescence are consistent and point out that the undoped CdSe film present excitonic features at low temperature, differently from CdSe:Zn films, whose spectral features are related to band–band transition. The luminescence efficiency of CdSe:Zn persists up to room temperature, whereas the luminescence of undoped CdSe is scarcely visible above 250 K.