Enhanced Photostability of Hollow Mixed Halide Wide-Bandgap Perovskite Films

We investigated the role of hollow perovskite architectures in enhancing the photostability of mixed halide wide-bandgap perovskites. We focused on mitigating photoluminescence (PL) peak shifts caused by phase segregation when exposed to light. By analyzing the optical and structural properties of mixed bromide/iodide hollow perovskite thin films, we observed that the incorporation of hollow structures reduced the ionic conductivity in the films, leading to improved photostability compared to non-hollow perovskite samples. The mixed halide hollow perovskite thin films exhibited increased the bandgap. High-power laser irradiation was used to induce phase segregation, and changes in the PL emission spectra were measured as a function of irradiation time. The mixed halide hollow perovskite thin films exhibited reduced PL peak shifts compared to the control samples. The inclusion of enI(2) (en = ethylene-diamine) resulted in a reduction in the overall ionic conductivity of the films and a lower trap density. Hollow perovskite films incorporated in solar cells indicated that while the initial efficiency of the solar cells decreased with increasing enI2 concentration, the open-circuit voltage value increased, potentially due to the slight enhancement of the band gap. The findings highlight the potential of hollow perovskite architectures in enhancing the photostability of mixed halide perovskites.

Automated summary

This study investigated the use of hollow perovskite architectures to enhance the photostability of mixed halide wide-bandgap perovskites. By analyzing the properties of hollow perovskite thin films, it was found that the incorporation of hollow structures improved photostability compared to non-hollow samples. The inclusion of enI(2) further reduced ionic conductivity and trap density. While the initial efficiency of solar cells decreased with increasing enI2 concentration, the open-circuit voltage value increased, potentially due to the enhancement of the band gap. Overall, hollow perovskite architectures show great potential in enhancing the photostability of mixed halide perovskites.