Recent advances and opportunities in perovskite-based triple-junction tandem solar cells

As the demand for sustainable energy sources increases, the multi-junction solar cell is an attractive approach to achieve high-energy density, overcoming the efficiency limit of single-junction solar cells. Halide perovskites are promising materials for multi-junction solar cells due to the ease of bandgap tunability and low-cost fabrication processes. Based on massive efforts for technological advances over a decade, single and double-junction devices using perovskite materials have been breaking world efficiency records, however, triple-junction solar cells have not yet received much attention. To achieve high-performing perovskite-based triple-junction tandem cells, several issues have to be resolved. In this paper, we discuss the status of perovskite-based monolithic triple-junction solar cells and the main issues for the advances in three parts: top, middle, and bottom subcells. In each part, a summary of the research challenges and achievements in improving the efficiency and stability of each subcell is presented, followed by the results of their application to triple-junction solar cells.