Cadmium sulfide (CdS) is a prominent material for its tunable band gap used as a window layer in II–VI
semiconductor solar cells. The light trapping capability of window layer is one of the powerful tools to
enhance the efficiency of the cell. CdS and zinc (Zn) powders were mixed mechanically with different
weight percents to make CdZnS (CZS) powder. CZS was deposited onto an ultrasonically cleaned glass
substrate using close spaced sublimation (CSS) technique. CZS as-deposited thin films were characterized
for structural, surface morphology with energy dispersive X-rays (EDX) and optical properties for the use
of window layer in CdS/CdTe based solar cells. The different Zn concentrations in CZS played a vital role
on crystallite size in structural analysis and optical properties e.g. transmission, absorption coefficient
and energy band gap, etc. The crystallite size of as-deposited CZS thin films were increased as Zn concentration
was increased up to certain value. The energy band gap varies from 2.42 eV to 2.57 eV for asdeposited
CZS thin films with increasing Zn concentrations and surface morphology changes also. These
changes were occurred due to zinc diffusion in CdS thin films. An angle resolved transmission data was
taken to check the behavior of CdS and CZS thin film at different angles. A comparative study was carried
out between CdS thin films and CZS thin films for the use of good window layer material.