Sunny delight

The slow, but inexorable climb to more and more efficient solar energy conversion materials takes another step forward. Scientists at the Swiss Federal Laboratories for Materials Science and Technology (EMPA), have developed thin film solar cells using copper indium gallium diselenide on flexible polymer foils. They claim a new record efficiency of 20.4% for conversion of sunlight to electricity. The development could increase dramatically the cost-effectiveness of solar power although the technology now needs additional testing, development and scale-up for industrial applications.