Investigating the Impact of Annealing Temperature on CdS Nanoparticles: Optimizing Solar Photovoltaic Efficiency

Abstract

The development of solar photovoltaic (PV) technology in the era of nanotechnology plays a crucial role in the advancement of renewable energy technologies. CdS is a vibrant candidate for numerous applications and the properties of CdS nanoparticles could be tailored and enhanced by annealing treatment. The present work unveils the impact of air annealing temperature on the tailoring of microstructural and optical properties of CdS nanoparticles. A facile chemical co-precipitation technique is employed to synthesize the CdS nanoparticles followed by annealing at 200°C and 400°C for 1 hour. The XRD patterns exhibit that nanoparticles are crystallized in hexagonal wurtzite crystal structure with (002) and (101) preferred orientations depending upon the annealing condition where the interplanar spacing and crystallite size corresponds to preferred peaks concerned ranging from 3.15-3.34 Å and 13-24 nm, respectively. Optical analysis reveals that transmittance is found less than 20% up to 500 nm and then abruptly increases in higher visible regions. The absorbance of nanoparticles is improved with annealing whereas band gap decreased from 2.19 eV to 2.02 eV. EDS pattern of as-grown samples confirmed the impurity-free synthesis of CdS nanoparticles. The FESEM micrographs revealed the formation of nano spherical grains for as-grown samples while nanoflake-like grain structures are visible for 400°C annealed nanoparticles. The novelty of this study lies in its comprehensive exploration of the impact of annealing temperature on the microstructure and optical characteristics of CdS nanoparticles.