Empa researchers are celebrating a new record. They have improved the efficiency of energy conversion in CIGS solar cells on flexible polymer substrate to 20.8 per cent. This is 0.4 per cent higher than the previous mark set by the same Empa research group. CIGS solar cells are a type of solar cell based on copper indium gallium diselenide (CIGS). According toEmpa, the material is particularly useful in the manufacture of flexible, lightweight solar cells on polymer films.
The new record is the result of a combination of three major improvements, explained Romain Carron, Head of CIGS research at Empa's laboratory in Dübendorf. He said: "First, we have carefully adjusted the chemical composition of the absorber layer to improve its electronic and optical properties. Then we developed new methods for alkali metal doping. And finally, we have adapted the properties of the absorber-buffer interface to improve cell performance."
While future developments will seek to transfer the new process to industrial scale, flexible CIGS solar modules are already commercially available. One vendor is Flisom, an Empa spinoff in Niederhasli in the canton of Zurich.