Optoelectronic Properties of PbS Films: Effect of Carrier Gas

In this study, lead sulfide (PbS) films were grown on Fluorine-doped TinOxide (FTO) glass substrate by thermal evaporation in a horizontal furnace toinvestigate carrier gas effect on structural, morphological, elemental, optical, electricaland photovoltaic properties of PbS. X-ray diffraction (XRD) patterns confirmed theformation of cubic polycrystalline PbS particles for all samples. The results showed thatusing Ar+H2 as a carrier gas increased crystallite size of the film. Field emissionscanning electron microscopy (FESEM) images showed nano-dimension surfacemorphologies and revealed that using carrier gas can make the obtained films and theirsurface porosities more uniform and regular. Also, the elemental analysis demonstratesthat using mixed carrier gas provides a better stoichiometry for PbS film. Optical andelectrical evaluations indicated improvements in absorption intensity and electricalconductivity of the PbS film when using the mixed carrier gas. Finally, the depositedfilms were characterized as solar cells and their quality parameters (QP) were extractedand presented. The obtained results illustrate the improvement in QPs of PbS solar cellwhen using mixed carrier gas.