A Review on Optoelectronic and Photoconductive Properties of CdS–ZnS Nanocomposites Prepared via Chemical Routes

Abstract

CdS–ZnS nanocomposites have emerged as a significant class of semiconductor materials owing to their tunable optoelectronic and photoconductive properties, making them highly suitable for advanced device applications. This review provides a comprehensive analysis of the structural, optical, and electronic characteristics of CdS–ZnS nanocomposites synthesized via various chemical routes, including chemical bath deposition, sol–gel, co-precipitation, hydrothermal, and green synthesis methods. The integration of CdS and ZnS enables effective band gap engineering, allowing control over light absorption across the ultraviolet and visible regions. Special emphasis is placed on photoconduction mechanisms, including charge carrier generation, transport, recombination processes, and the role of defect states and interfaces in influencing device performance. The review also discusses the impact of synthesis parameters on morphology, crystallinity, and functional efficiency. Furthermore, key optoelectronic properties such as conductivity, response time, and sensitivity are critically examined in relation to their applications in photodetectors, solar cells, and light-emitting devices. Despite their advantages, challenges such as cadmium toxicity, stability issues, and scalability are highlighted. The study concludes by outlining future research directions focused on improving performance through material engineering and sustainable synthesis strategies.