Highly efficient organic tandem solar cells: a follow up review

Multi-junction solar cell configurations, where two or further sub-cells with complementary absorption are stacked and connected in series or parallel, offer an exciting approach to tackle the single junction limitations of organic solar cells and further improve their power conversion efficiency. In this article we aim to follow up our previous work and review the most important and novel developments that have been recently reported on organic tandem solar cells. In addition, some brief theoretical considerations addressing the potential of single and tandem solar cells, the working principles of the intermediate layer, the importance and benefits of optical simulations and finally the intricacies of a precise performance measurement of bulk-heterojunction organic tandem solar cells based on complementary absorber materials are presented.