Solar cells with the structure ITO-Cu-CdS/PbS-Ag were fabricated by heat-induced Chemical Bath Deposition (CBD) technique. Cu-doped CdS/PVA nanocomposite thin film of thickness 260 nm was used as the window layer. The PbS absorber layer of different thickness (528.3 -1250.8 nm) for different molar concentration of lead nitrate (0.05, 0.1, 0.15, 0.2 and 0.3 M) was then grown on ITO/CdS to fabricate the junction. The effect of molar concentrations on the optical and structural properties of the corresponding PbS films and solar cells were investigated. The optical bandgap of the PbS films was found to decrease with the increase of the molar concentration. The photovoltaic parameters such as short circuit current, open circuit voltage, fill factor and efficiency of the CdS/PbS solar cells were evaluated from the J-V characteristics under one sun illumination intensity (100mW/cm 2 ). The changing molar concentration enhanced the performances of the cells and a highest efficiency (1.38%) obtained at 0.3M molar concentration.