Investigation of Photoconductive Behavior in Chemically Synthesized CdS–ZnS Nanocomposites

Abstract

The present study investigates the photoconductive behavior of chemically synthesized CdS–ZnS nanocomposites with an emphasis on understanding charge transport mechanisms and the influence of compositional variation. CdS–ZnS nanocomposites were prepared using a controlled chemical route, enabling precise tuning of structural and optical properties through variation in Cd/Zn ratios. Structural and morphological analyses confirm the formation of nanoscale heterostructures with improved crystallinity and uniform particle distribution. Optical studies reveal tunable band gap characteristics arising from compositional control and quantum confinement effects, which significantly influence light absorption behavior. Photoconductivity measurements demonstrate enhanced photocurrent response under illumination due to efficient generation and separation of charge carriers at the CdS–ZnS interface. The role of defect states and surface traps is found to be critical in governing carrier recombination and transport dynamics. Additionally, the study examines the effect of illumination intensity and temperature on conductivity, providing insights into conduction mechanisms such as trap-assisted transport and band conduction. The incorporation of ZnS improves stability and reduces recombination losses, thereby enhancing overall performance. The findings highlight the potential of CdS–ZnS nanocomposites for applications in photodetectors and optoelectronic devices, while also addressing key challenges related to defects and material stability