The main aim of the research is to fabricate and enrich the electrical and power conversion efficiency behaviour of the CdTe layer configured with molybdenum (Mo-100 nm) and varied magnesium zinc oxide (MgZnO) buffer thickness of 20, 40, and 60 nm formed via thermal evaporation technique. The developed CdTe without and with MgZnO/Mo is experimentally investigated. The effect of buffer layer (MgZnO) layer thickness on transmittance, current–voltage (J-V), and power conversion efficiency behaviour of CdTe without and with MgZnO/Mo solar cell layers are investigated. The buffer thickness influences better optical and J-V performance compared to CdTe without the MgZnO/Mo layer. Based on the investigational results, the CdTe featured with 60 nm MgZnO with Mo layer is found to have good transmittance (63%), improved short circuit current density (Jsc) of 25.6 mA/cm2, higher open circuit voltage (Voc) of 0.78 V, and improved power conversion efficiency behaviour of 19.5%, which is better than the CdTe without buffer/Mo layer. However, XRD provided and confirmed the various concentrations of MgZnO in the CdS/CdTe layer and found better absorption coefficient and electrical conductivity behaviour (1.35 × 105 per cm and 1.9X 10–2 S/cm).