The University of Luxembourg’s Laboratory for Photovoltaics, which develops economical thin-film photovoltaic cells, has announced that its kesterite-based solar cells have registered 6.1% efficiency, which is a new European record certified by the Frauhofer ISE. The firm is authorized to issue certification on solar cell efficiencies.
Kesterite’s raw materials are mainly selenium, sulfur, tin, zinc and copper, which are found abundantly in nature and thus are low-cost, resulting in the production of cost-effective solar cells. Previously, a number of laboratories have registered issues during the deposition method concerning to the loss of tin, while preparing at high temperatures.
The loss of tin makes the proportion control of the thin film very difficult, resulting in improper composition and poor efficiency of the solar cell. The Laboratory for Photovoltaics has utilized a production method that eradicated such issues, resulting in solar cells with record efficiency in the first attempt of production. The Journal of the American Chemical Society has published a detailed report about the processing method.
The scientists began the production method with a precursor film of zinc and copper and added the remaining elements at a later stage. This approach simplified the fabrication method and made it easy to control and monitor material compositions.