Quantum Confinement and Trap-State Emission in Cds/Zns Nanoparticles Stabilized within A PVA Matrix

CdS/ZnS nanoparticles encapsulated within a polyvinyl alcohol (PVA) matrix were successfully synthesized via a simple solution-phase method and systematically investigated for their structural, optical, and morphological properties. UV–Vis absorption spectra exhibited a strong absorption band in the 200–220 nm region with a noticeable blue shift relative to bulk CdS and ZnS, confirming quantum confinement at the nanoscale. FT-IR analysis validated the presence of characteristic PVA functional groups along with distinct Cd–S and Zn–S stretching vibrations, confirming effective encapsulation of the nanoclusters within the polymer matrix. Photoluminescence spectra revealed broad visible-region emissions attributed to defect-related trap states, with Zn²⁺ incorporation influencing luminescence intensity. XRD analysis confirmed the nanocrystalline cubic zinc blende phase of CdS and ZnS, with crystallite sizes in the 10–20 nm range, while SEM micrographs showed agglomerated yet porous morphologies, offering enhanced surface area. The combined findings highlight the role of PVA in stabilizing CdS/ZnS nanoclusters, leading to nanocomposites with favorable structural and optical features. These results underscore the potential of CdS/ZnS/PVA nanocomposites for future applications in optoelectronic devices, photocatalysis, and electrochemical energy storage systems.