Optoelectronic Properties of PbS Films: Effect of Carrier Gas

In this study, lead sulfide (PbS) films were grown on Fluorine-doped Tin Oxide (FTO) glass substrate by thermal evaporation in a horizontal furnace to investigate carrier gas effect on structural, morphological, elemental, optical, electrical and photovoltaic properties of PbS. X-ray diffraction (XRD) patterns confirmed the formation of cubic polycrystalline PbS particles for all samples. The results showed that using Ar+H2 as a carrier gas increased crystallite size of the film. Field emission scanning electron microscopy (FESEM) images showed nano-dimension surface morphologies and revealed that using carrier gas can make the obtained films and their surface porosities more uniform and regular. Also, the elemental analysis demonstrates that using mixed carrier gas provides a better stoichiometry for PbS film. Optical and electrical evaluations indicated improvements in absorption intensity and electrical conductivity of the PbS film when using the mixed carrier gas. Finally, the deposited films were characterized as solar cells and their quality parameters (QP) were extracted and presented. The obtained results illustrate the improvement in QPs of PbS solar cell when using mixed carrier gas.