Solar cells with 11% efficiency on ribbon-growth-on-substrate (RGS) silicon

Solar cells have been prepared on Bayer ribbon-growth-on-substrate (RGS) crystalline silicon. This low-cost material contains a fair amount of impurities and crystal defects whose adverse effect on solar cell performance may be significantly reduced by gettering and bulk passivation treatments. This is demonstrated in solar cells by having a mechanical surface texturization, an aluminium gettering as well as a hydrogen passivation step which led to an open circuit voltage Voc of 538 mV, a short circuit current density Jsc of 28·5 mA cm−2, a fill factor of 72·4% and a confirmed record efficiency β of 11·1% (2×2 cm2). Strong improvements in the diffusion length could be observed after the hydrogen treatment.