The correlation between the As to group III flux ratio and photovoltaic performance of Galn(0.1)N(0.03)As solar cells fabricated by molecular beam epitaxy is systematically investigated. The results show that flux ratio has a remarkable influence on the formation of defect traps. Furthermore, the formation of defects at different flux ratios is correlating with the variation of the background doping level and the photovoltaic performance. In particular, this study reveals a linear dependency between current generation, dark saturation current, defect densities, photoluminescence peak intensity and the flux ratio. A significant increase in solar cell performance, exhibiting maximum external quantum efficiency of 90%, is obtained when As/group-III ratio is decreased close to the stoichiometric limit. For optimized growth condition, the 1 eV Galn(0.1)N(0.03)As solar cell exhibits a short circuit current density as high as 17.9 mA/cm(2) calculated from the external quantum efficiency data (AMO conditions) with 870 nm high-pass filter. This value reflects the potential of the GaInNAs cell for current matching and power generation in high efficiency solar cells incorporating three- or four- junctions. (C) 2016 Elsevier B.V. All rights reserved.