Influence of the S/Cd ratio on the luminescent properties of chemical bath deposited CdS films

Usually as-grown chemical bath deposited Cadmium sulfide (CdS) samples do not show luminescence at room temperature because of the high density of recombination centers due to many defects generated during the growth process, particularly for chemical bath deposited CdS films. The change of the S/Cd ratio allows to control the density of defects giving rise to a better quality CdS films which can show luminescence at room temperature. Depending on the S/Cd ratio an evolution and improvement of the photoluminescence signal at room temperature is observed.