Nanoarchitectonics of wide-bandgap perovskite films using sputtered-PbI 2 precursor and ion-exchange method

Conformal deposition of wide-bandgap perovskite films along pyramidal silicon surfaces through the dry process is essential for fabricating large-area textured silicon/perovskite tandem solar cells. However, it is difficult to control the composition of mixed perovskite films through dry processes because the deposition rate in organic and inorganic components is different when depositing perovskite films using a multi-source or premixed-source. In this study, MAPbI 3 perovskite films were deposited through radio-frequency magnetron sputtering and dry conversion processes, and wide-bandgap perovskite films with mixed halide compositions were prepared by immersion in a MABr/IPA solution. Based on the results, the bandgap of the perovskite films increased with the immersion time. In addition, a uniform depth profile of the perovskite composition was observed in the film. Perovskite solar cells were manufactured to verify their electrical characteristics. Finally, wide-bandgap perovskite films were conformally deposited on textured silicon surfaces. These results show the great potential of applications in silicon/perovskite tandem solar cells.