Improved InxGa1_xP/GaAs /Ge tandem solar cell using light trapping engineering and multi-objective optimization approach

In this paper, an analytical model for studying the effect of light trapping mechanism on tandem solar cell performance is developed. The proposed model considers diffraction grating morphology and antireflection coating of the InxGa1_xP/GaAs/Ge tandem solar cell. The main photovoltaic figures of merit of the InxGa1_xP/GaAs/Ge tandem solar cell are investigated. The obtained results prove the outstanding capability of the light trapping mechanism to improve device performance. An efficiency of 32.5% was obtained. A short circuit current density (JSC) of 28 mA/cm2, an open-circuit voltage (VOC) of 1.288 V, and a fill factor (FF) of 87.7% were calculated. In addition, the developed model serves as a fitness function to optimize the light trapping capability using a multi-objective particle swarm optimization (MOPSO) approach. The optimized tandem solar cell design exhibits higher performance characterized by JSC =35.3 mA/cm2, VOC = 1.305 V, and a conversion efficiency of 41.7% which outweighs that of the conventional planar solar cell. Therefore, the proposed design methodology efficiently minimize the reflectance via establishing an intensive light trapping mechanism at the front of both subcells and opens promising opportunities to enhance the tandem solar cell performances.