Synthesis of PbS:Mo(3%) thin film and investigation of its properties

Pure PbS and PbS:Mo(3%) thin films were synthesized on glass substrates at room temperature using the chemical bath deposition (CBD) method. The main purpose of this study is to examine the effect of the Mo additive metal on the crystallite size, optical energy band gap and photovoltaic properties of the PbS semiconductor thin film. Although the structure of PbS:Mo(3%) thin film was the same as the pure PbS, the crystallite size of PbS:Mo(3%) thin film (24.12 nm) was found to be lower than that of pure PbS (25.97 nm). The band gap values of PbS and PbS:Mo(3%) thin films were obtained as 1.89 eV and 1.91 eV, respectively. The possible reason for the increase in the energy band gap of PbS:Mo(3%) thin film is the incorporation of Mo⁶⁺ ions into the PbS lattice. Photovoltaic properties of PbS and PbS:Mo(3%) thin films synthesized on Zn₂SnO₄ coated on FTO conductive glasses via CBD technique were investigated using the IPCE and J–V measurements. The IPCE (%) values obtained at 400 nm for the pure PbS and PbS:Mo(3%) thin films were 35% and 41%, respectively. The power conversion efficiency (η) values were obtained as 2.02% and 2.11% for pure PbS and PbS:Mo(3%) thin films, respectively. Thus, it was observed that the doped metal has significantly improved the photovoltaic properties of PbS thin films.