Solar cells for window applications

Abstract

Organic solar cells have the potential to provide low-cost photovoltaic devices as a clean and renewable energy resource, offering flexibility and easy processing. In addition, by choosing different materials for the active layer, the solar cells can be tuned to colourful aesthetic semi‐transparent devices, which designers and architects can explore, e.g., for window designs. In this paper, we will try to enhance absorption in the active layers and thus efficiency of semi-transparent devices by using tandem bulk heterojunction solar cell architecture. We will have a look on two difference active layer as the first solution blend will be made of PCPDTBT (donor) and PCBM (acceptor), whose absorption peak is at the red-infrared part of the solar spectrum, while the second active layer will be made from P3HT (donor) and PCBM (acceptor), whose absorption peak is at the blue-green part of the spectrum. As the absorption ranges of these two active layers are complementary, the resulting absorption will cover a wider spectral range, enhancing the power conversion efficiency. At the same time, the semi-transparency of the solar cells will be optimized by controlling the thicknesses of the layers. To be sure that the solar cells are getting semi-transparent the electrodes must also be semi-transparent, and this will be made from ITO and from commercially available conductive polymers.