This paper presents the current voltage (IV) characteristics analysis of III-V semiconductors, Gallium Arsenide (GaAs) and Indium Phosphide (InP) homojunction solar cell under standard illumination AirMass-1.5D (AM1.5D) spectrum using MicroTec- simulator. The IV characteristics curves signify the use of GaAs with 86.22% Fill Factor (FF) and 28.5% efficiency instead of InP with 82.48% FF and 24% efficiency in photovoltaic (PV) unit. The influence of change in doping profile and temperature of GaAs solar cell is simulated for improving the device performance. Due to the substantial increase in base doping concentration, increase in Maximum Power Output (Pm), FF and efficiency have been noticed. We have observed 0.684% per °C decrease in Pm along with 0.1% per °C decrease in efficiency from the GaAs photovoltaic cell.