High performance tandem perovskite-silicon solar cells with very large bandgap photoelectrodes

Nanostructured layers of metal oxides with very large bandgaps ($E_g>5$ eV), such as ZrO$_2$ and HfO$_2$, were used as photoelectrodes in semitransparent perovskite solar cells (PSCs) with the device architecture of glass/FTO/c-TiO$_2$/ZrO$_2$ (or HfO$_2$)/CH$_3$NH$_3$PbI$_3$/PTAA/PEDOT:PSS/FTO/glass. The obtained PSCs were used as top elements for manufacturing high-performance four-terminal tandem perovskite-silicon solar cells. The comparative analysis of photovoltaic parameters measured for PSCs, crystalline silicon (c-Si) solar cells and tandem PSC/c-Si solar cells demonstrated that the application of very large-bandgap materials allows to improve the PSC performance and to increase the efficiency of tandem PSC/c-Si solar cell up to $\sim24\%$ in comparison with a standalone c-Si solar cell.