A Rapid and Robust Light-and-Solution-Triggered In Situ Crafting of Organic Passivating Membrane over Metal Halide Perovskites for Markedly Improved Stability and Photocatalysis.

Liu, Fangyan; Wang, Mengye; Liu, Xiaolong; Wang, Biao; Li, Caifu; Liu, Chenning; Lin, Zhang; Huang, Feng · Nano Lett · 2021

basic_science · Level V

Where this comes from

Abstract

Despite intriguing optoelectronic attributes in solar cells, light-emitting diodes, and photocatalysis, the instability of organic-inorganic perovskites poises a grand challenge for long-term applications. Herein, we report a simple yet robust strategy via light-and-solution treatment to create an organic membrane that effectively passivates CH<sub>3</sub>NH<sub>3</sub>PbI<sub>3</sub> (MAPbI<sub>3</sub>). Specifically, the restructuring of MA<sup>+</sup> is observed on MAPbI<sub>3</sub> in aqueous hydrogen iodide. HIO<sub>3</sub> molecules are generated via the reaction between water and I<sub>2</sub> induced by photocatalysis when MAPbI<sub>3</sub> is illuminated. The hydrogen bonding between HIO<sub>3</sub> molecules at different perovskite particles not only directs the creeplike growth of perovskite particles but also in situ forms a passivating layer firmly anchoring on the perovskite surface with hydrophilic -NH<sub>3</sub><sup>+</sup> groups tethering to perovskites and hydrophobic -CH<sub>3</sub> moieties exposed to air. Intriguingly, such MA<sup>+</sup> film greatly improves the stability of perovskites against moisture as well as their crystal quality, considerably enhancing the photocatalytic hydrogen evolution rate.