Improvement of carriers diffusion length and mobility in annealed GaAsPN materials for intermediate band solar cells

Abstract In this paper, we investigate the effect of thermal annealing on nonradiative recombination parameters of GaAsPN materials used for intermediate band solar cells. This study is performed thanks to photothermal deflection technique PTD. Indeed, nonradiative lifetime, electronics diffusivity, surface and interface recombination, are extracted through a good fit between theoretical and experimental amplitude and phase of PTD signal. Then, the effects of annealing temperature on charge transport were analyzed and discussed. As an important result for solar cells improvement, we have found that hole diffusion length and mobility increases respectively from 13.8 to 19 (±2.5%) μm and from 112 (±4.9%) to 153 (±3.5%) cm2/V·s for GaAsPN as grown to that annealed at 800 °C.