Temperature Dependent Hydrogen Bond Toward High Emission in an Emerging Indium‐Based Perovskite

Abstract Low‐dimensional organic–inorganic hybrid perovskites (OIHPs) with broadband emission attract immense scientific interest due to their potential application for the next generation of solid‐state lighting. However, due to low exciton utilization, organic cations generally adjust structure rather than contribute the band edge to affect optical properties. Based on this, OIHPs are usually allowed to obtain a low photoluminescence quantum yield (PLQY). Herein, a good charge transfer carrier (p‐phenylenediamine, PPDA) as organic cation is rationally employed and a novel indium‐based perovskite is synthesized. By coupling with H₂O molecules, a strong interaction between organic and inorganic components is realized by hydrogen bonding, which has good transportability and greatly improves the exciton utilization. The regions of hydrogen bonding show high electron mobility, combined with the induced recombination center, improving the progress of charge relaxation. As a result, the regulation of hydrogen bond strength based on the microstructure optimization directly determines the optical emission intensity, realizing nearly 100% PLQY. Further, the polyhydrogen bond structure makes each component a stronger interaction, showing high stability in polar, organic, and acidic solvent, as well as long‐term storing, which represents one of the highest overall performances for lighting in OIHPs.