Trapped-Hydrogen-Induced Energy Loss in Tin-Based Hybrid Perovskite Solar Cells

The hitherto subdued power conversion efficiencies of Sn-based hybrid perovskite solar cells are gener-ally attributed to severe nonradiative recombination; however, the responsible deep-level defects are still unclear. Here, we report an important nonradiative energy loss mechanism in the prototypical FASnI3 [FA = HC(NH2)2, formamidinium]. High-density tin vacancies (VSn) can effectively capture hydrogen to form VSn - H2 complexes that act as highly detrimental nonradiative recombination centers. We quan-titatively show that they can give rise to strong carrier recombination and thus energy loss due to a high nonradiative recombination rate constant. These key findings identify a hidden yet critical origin for the low performance of FASnI3-based devices and highlight the significance of controlling the hydrogen environment in the development of broad high-efficiency nontoxic halide perovskite device applications.

Automated summary

The research reveals that the poor performance of FASnI3 perovskite solar cells is attributed to high-density tin vacancies (VSn) capturing hydrogen to form nonradiative recombination centers. Controlling the hydrogen environment is crucial for developing efficient and non-toxic halide perovskite device applications.