Highly read on pubs.acs.org in April

A sprinkling of nitric acid doubles the efficiency of hybrid silicon–nanotube photovoltaic cells.

Typical hybrids, made of networks of carbon nanotubes laid on crystalline silicon, might be cheaper to make than conventional all-silicon cells. Yet, at best, they convert a meagre 6–7% of sunlight's power into electricity, well under half the performance of commercial silicon cells. Anyuan Cao at Peking University, Beijing, Dehai Wu at Tsinghua University, also in Beijing, and their colleagues show that adding dilute nitric acid boosts the hybrids' efficiencies to 11–13%. The acid improves contact between the silicon and the nanotubes, providing more paths for charge carriers to exit the cell and produce external current.

Nano Lett. doi:10.1021/nl2002632 (2011)