Synthesis of Fe alloyed PbS thin films and investigation of their photovoltaic properties

Lead sulfide (PbS) and iron (Fe)-alloyed PbS thin films with different Fe concentrations were synthesized by chemical bath deposition (CBD) technique, which is suitable for cost on glass substrates at room temperature. The structural, elemental and optical properties of the synthesized thin films were characterized by X-ray diffraction (XRD), energy dispersive X-ray (EDX) and optical absorption measurements, respectively. It was observed that Fe dopant alters crystal size and energy band gap of PbS although it does not change the structure of PbS. PbS and Fe-alloyed PbS thin films with different Fe concentrations were grown on zinc tin oxide (Zn₂SnO₄) substrates coated on fluorine-alloyed tin oxide conductive glasses to investigate their photovoltaic properties. Incident photon-to-current efficiency (IPCE) and current density (J)–voltage (V) measurements were carried out to determine IPCE (%) and power conversion efficiency (η%) values of thin films. As a result, it was observed that as the concentration of Fe dopant is increased in Fe-alloyed PbS thin films, there is an increase in η%.