Enhancing the Performance of Thin-Film Photovoltaic Cells via the Application of Luminescent Down-Shifting Layers

Photovoltaic (or solar) cells made from copper indium gallium diselenide (CIGS) are one of the most promising thin film technologies to achieve commercialisation. However, a cadmium sulphide window layer that is essential for good electronic performance of the device absorbs a significant fraction of sunlight below 520nm in wavelength. By placing a luminescent down-shifting layer in front of the solar cell that absorbs these wasted photons and re-emits them at longer wavelengths, an efficiency increase by up to 30% can be realized. Such a performance boost to the technology could greatly enhance the technology s potential to penetrate the photovoltaic market.