Minimizing the Ohmic Resistance of Wide-Bandgap Perovskite for Semitransparent and Tandem Solar Cells.

To overcome the efficiency limit of perovskite single-junction solar cells, it is vital to develop various types of tandem solar cells. Especially, wide-bandgap (WBG) perovskite solar cells (PSCs) have played an important role in high-efficiency tandem solar cells. Herein, an indium zinc oxide-based interfacial structure is developed to improve the performance of a WBG PSC and used as the transparent electrode for semitransparent (ST) PSCs. This approach minimizes ohmic contact between the electron-transport layer and metallic electrode, which also accelerates electron transfer and suppresses trap-assisted carrier recombination. As a result, the WBG PSC (1.71 eV) shows the best power conversion efficiency of 19.26% and improves operational stability. When the optimized ST-PSC is used as the ST-top cell, perovskite/CdTe four-terminal and perovskite/silicon (doubleside polished) two-terminal tandem solar cells achieve a maximum efficiency of 22.59% and 26.34%, respectively. [ABSTRACT FROM AUTHOR]