Influence of deposition temperature and fluorine doping on CdS properties: Exploring applications in CdTe solar cells

• Pure CdS and F-doped CdS thin films were manufactured using the CBD technique. • The investigated parameters were affected by F doping and deposition temperature. • F doping enhances the photovoltaic performance of CdS/CdTe solar cells. • CdS:F films have the potential to be implemented in optoelectronic devices. CdS and CdS:F thin films were synthesized at 75 °C and 90 °C by CBD with NH 4 F as the fluorine dopant. The structural, morphological, optical, and electrical properties were investigated with varying F wt.%. XRD analysis revealed a coexistence of cubic and hexagonal phases with small crystallite sizes. Raman spectroscopy exhibited characteristic peaks of 1LO and 2LO, corresponding to longitudinal optical phonons. Scanning electron microscopy (SEM) images displayed dense films with excellent substrate adhesion and crystalline morphology. Optical analyses unveiled noticeable alterations in optical transmittance due to F doping, with bandgap values ranging between 2.3 to 2.4 eV. Electrical resistivity, typically in the order of kΩcm, was influenced by incorporating F atoms within the CdS lattice. Notably, the fabrication of CdS/CdTe solar cells yielded efficiencies of 5.53 % for undoped CdS films and 7.47 % when utilizing films doped with 0.00455 wt% fluoride, highlighting the beneficial impact of F incorporation on solar cell performance.