Role of radiative recombination in 1 eV GaInNAs solar cells

High quality GaInNAs p-i-n solar cells with depletion widths in excess of 1$\mu $m for material absorbing in the practically important 1eV band gap regime are presented [1]. This is achieved through optimization of post-growth rapid thermal annealing at a temperature of $\sim $ 910\r{ } C. Despite the improvements in material quality evidenced by a low background impurity concentration and improved minority carrier collection, the external quantum efficiency remains limited to $\sim $ 50{\%}. This is attributed to losses due to efficient radiative recombination in the bulk GaInNAs intrinsic region enhanced via localization of carriers in alloy fluctuations. \\[4pt] [1] Sellers \textit{et al}. Applied Physics Letters \textbf{99}, 151111 (2011)