Highly read on pubs.acs.org 21 Mar–18 April

A light-harvesting crystal can make efficient, colourful and low-cost devices that convert sunlight into electricity.

Researchers led by Sang Il Seok at the Korea Research Institute of Chemical Technology in Daejeon, South Korea, created metal–organic hybrid materials that were composed of lead; methylammonium; and iodine or bromine, or both. Semiconductors used in solar cells can be coated in these materials, which absorb light and displace electrons that the semiconductor transfers to an external circuit. By varying ratios of bromine and iodine, the researchers tuned the material's stability and light-absorption properties to produce solar cells with a variety of translucent colours, from dark brown to yellow. On average, the cells could convert 10% of sunlight energy into electricity, with a maximum of 12.3% — a performance that matches competing low-cost options.

Nano Lett. http://dx.doi.org/10.1021/nl400349b (2013)