Simulation and optimization of current and lattice matching double-junction GaNAsP/Si solar cells

• Theoretical investigation of current and lattice matched GaNxAsyP1−x−y/Si double-junction solar cells.
• The nitrogen and arsenic concentrations ensuring lattice matching to Si are determined.
• The band gap of GaNAsP is calculated using the band anti-crossing model.
• Optimum compositions of the top sub-cell have been identified.
• The simulation results predict, for the optimized GaNAsP/Si double-junction solar cell, a conversion efficiency η = 37.5%.

This paper deals with theoretical investigation of the performance of current and lattice matched GaNxAsyP1−x−y/Si double-junction solar cells. The nitrogen and arsenic concentrations ensuring lattice matching to Si are determined. The band gap of GaNAsP is calculated using the band anti-crossing model. Calculations were performed under 1-sun AM1.5 using the one diode ideal model. Impact of minor carrier lifetime and surface recombination in the top sub-cell on the cell performances is analyzed. Optimum compositions of the top sub-cell have been identified (x = 4.5%, y = 11.5% and Eg = 1.68 eV). The simulation results predict, for the optimized GaNAsP/Si double-junction solar cell, a short circuit current Jsc = 20 mA/cm2, an open circuit voltage Voc = 1.95 V, and a conversion efficiency η = 37.5%.