Researchers at Empa (the Swiss national research laboratory) have achieved a new record in thin-film solar cell efficiency. The flexible solar cells are made from copper indium gallium diselenide (CIGS), and these cells have achieved an energy conversion efficiency of 18.7 percent.
The previous record of 17.6 percent was achieved only a year previously (and by the same research group, too). This represents more than 6% improvement in the course of only a year. While that’s not indicative of a larger trend, it is still a positive development.
Other kinds of solar cells have higher efficiencies, but the importance of thin-film efficiency has to do with economics of manufacture. Thin-film solar cells are inexpensive to produce, and, because of their physical flexibility, they are adaptable for use in a range of applications. Thin-film solar cells also offer perhaps the best possibility for cheaper-than-coal electricity.