Solar cells are semiconductor devices that turn light into electricity. The performance analysis of a Gallium Arsenide (GaAs) based solar cell model was shown using the Analysis Microelectronic and Photonic Structures (AMPS-1D) simulator in this work. A balance of semiconductor compositions, layer thicknesses, and other factors had been studied. The effect of temperature on efficiency has been explored, as the thickness of the top gallium indium layer (GaInP). As the amount of phosphorus in double junction solar cells decreases, the efficiency increases. An efficient and optimised BSF layer is a key layer in both single junction and multi junction solar cells. The use of dual layer BSF for top cells with different thicknesses is explored in this GaInP/GaAs dual junction solar cell study using the Silvaco ATLAS computer numerical simulation TCAD tool. A low-high junction at the back end of a gallium arsenide solar cell has been studied. A back surface field (BSF) is generated by the n⁺ layer at the rear end of a standard p⁺n junction solar cell, which improves the open-circuit voltage, short circuit current, fill factor, efficiency, and spectrum response.