In this study, the enhanced performance of a triple–junction GaAs–based solar cell using a SiO2
graded–index antireflection coating (GI–ARC) was demonstrated. The optical reflectance, photovoltaic current–voltage (I–V), and external quantum efficiency (EQE) of a cell with a SiO2
double–layer (DL) ARC and a cell with a GI–ARC were measured and compared. The cell with a GI–ARC exhibited the lowest optical reflectance. Thus, the average EQE enhancements (ΔEQE) of the cell with a GI–ARC compared to the cell with a DL–ARC were 5.88% for the top cell and −1.56% for the middle cell. In addition, a small difference in the photocurrent generated between the top cell and the middle cell was achieved. Finally, an additional 0.52% increase (from 24.99% to 25.51%) in conversion efficiency was obtained.
Keywords: current matching, external quantum efficiency, graded–index antireflection coating, SiO2 nanopillars, silicon dioxide, silica, triple–junction solar cells, nanoelectronics, nanotechnology, gallium arsenide, GaAs, optical reflectance, photovoltaic current voltage, photocurrent, conversion efficiency