Enhancement of diffusion length in EFG ribbon solar cells under illumination

The short-circuit current, efficiency, and minority-carrier diffusion length of EFG ribbon silicon solar cells have been measured as a function of illumination level between 0 and 5 suns and found to increase. The faster rate of increase of the current in ribbon cells compared to CZ we attribute to the enhancement of the minority-carrier diffusion length under illumination. A quasicontinuous deep-trap model with a Gaussian distribution of compensated donor states is proposed to account for these observations.