The purposes of PV cells are to transfer light energy into electrical energy. A compelling BSF is a key basic component for a productive PV cell.. In this paper, two significant materials GaAs and InGaP with top BSF and base BSF cells are researched utilizing the computational numerical modelling TCAD tool based Silvaco ATLAS. Past research observed that on the current coordinating condition with top BSF layer and base BSF layer, the cell show a general upgrade of density in Isc (short circuit current) and Voc (open circuit voltage) subsequently improving the overall efficiency of the cell. In this paper, structure of various thin film PV cells based on III-V materials e.g. GaN, InGaN have been used to design the multi junction PV cells. Extraction of figures of merits (efficiency, open circuit OC voltage, short circuit SC current and fill factor), simulation of electrical and optical characteristics of these devices have been carried out in this work. Our focus is to improve the optical characteristics, refractive index and absorption coefficient of InGaP with BSF and tunnelling features. In this paper complete Simulation and experimental results are shown and compared. The objective of this paper is to examine the productivity of InGaP/GaAs PV cells utilizing the Silvaco Atlas TCAD simulation software. © BEIESP.