Modeling and Simulation of Thin Film InP/GaAs Dual-Junction Solar Cells

We report the modeling and simulation results of thin film InP/GaAs dual-junction solar cell devices. The photovoltaic devices of varying device thickness in a range of 1-5 µm were modeled and optimized by modulating hole and electron concentrations in p-and n-doped active layers, respectively, and the thickness of the n-and p-regions in the devices. Our findings show that, with an increase in the thickness of active layers, the efficiency of solar cells increases which resulted in efficiency values in a range of 31.8%-36.4% under 1 sun of AM1.5G at 300 K. Furthermore, the optimized solar cells were further investigated under different working temperatures, black body temperatures, and solar spectra. For the working temperature range of 300 K-373 K, the efficiency of the device degraded with the increase in temperature. In the black body temperature range of 2000-8000 K, the device exhibited an enhancing trend of efficiency when temperature increased and the highest efficiency of 31.9% was achieved at 6500 K. Due to their lightweight, low cost with much thinner device structure, and higher energy conversion efficiency, the thin film solar cells demonstrated here have advantages over conventional Si or other semiconductors-based solar cells for applications in photovoltaic, thermal photovoltaic, and space power.