Photoluminescence Study of Ammonium-Free Chemical Bath Deposition of CdS Nanoparticles on Polyester Substrate

Self-assembled cadmium sulfide (CdS) thin solid films were synthesized by chemical bath deposition (CBD) technique for different deposition times (20 min.–24 h) on transparent and flexible polyester substrates using sodium acetate complex agent. CBD-CdS films were also deposited on glass (BK7) and quartz substrates, as reference. CBD-CdS films on polyester substrate showed a homogeneous deposition, reduction of chemical or structural defects (green emission), and large photoluminescence efficiency in comparison of CBD-CdS films deposited on Si-based substrates. Simulation of PL temperature dependence for polyester CdS films using the rate equation for the carrier population showed the presence of two decay pathways due to cadmium and sulphide defects at crystallite.