Fabrication and characterisations of n-CdS/p-PbS heterojunction solar cells using microwave-assisted chemical bath deposition

► n-CdS/p-PbS heterojunction solar cell was fabricated using MACBD method. ► XRD analysis confirms the formation of pure and nanocrystalline CdS and PbS. ► SEM revealed that CdS thin film covered completely, no pinholes or cracks. ► All PbS films have uniform surface morphology over the substrate with gatherings. ► Molar concentration improved the performances of the fabricated photovoltaic cells. n-CdS/p-PbS heterojunction solar cells were prepared via microwave-assisted chemical bath deposition method. A cadmium sulfide (CdS) window layer (340nm thickness) was deposited on an indium tin oxide (ITO) glass. A lead sulfide (PbS) absorber layer (985–1380nm thickness) with different molar concentrations (0.02, 0.05, 0.075, and 0.1M) was then grown on ITO/CdS to fabricate a p–n junction. The effects of changing molar concentration of the absorber layer on structural and optical properties of the corresponding PbS thin films and solar cells were investigated. The optical band gap of the films decreased as the molarity increased. The photovoltaic properties (J–V characteristics, short circuit current, open circuit voltage, fill factor, and efficiency) of the CdS/PbS heterostructure cells were examined under 30mW/cm2 solar radiation. Interestingly, changing molar concentration improved the photovoltaic cells performances, the solar cell exhibited its highest efficiency (1.68%) at 0.1M molar concentration.