Near-unity emission in zero-dimensional Sb(III)-based halides intervened by hydrogen bonds towards efficient solid-state lighting technology

Abstract

Zero-dimensional (0D) metal halides have garnered considerable interest owing to their superb optical characteristics, and adaptable architectures. Two 0D organic-inorganic metal halides (OIMHs) (C20H20P)2SbCl5·(EA) ([C20H20P]+ = ethyltriphenylphosphine) and (C20H20P)2SbCl5·(IPA) were successfully synthesized and investigated using a simple solvent-evaporation approach. These OIMHs possess a similar structure, except for the solvent molecules in the lattice, however, their photoluminescence quantum yields (PLQYs) exhibit a considerable difference, with 99.82% in (C20H20P)2SbCl5·(EA) and 73.7% in (C20H20P)2SbCl5·(IPA). Bond-order and crystal orbital Hamilton population (COHP) calculations reveal that (C20H20P)2SbCl5·EA system exhibits stronger hydrogen bonds, leading to stronger supramolecular interactions, which suppress non-radiative transition. The experimental results and density functional theory (DFT) calculations suggest an increase in PLQY, which could be attributed to the stronger hydrogen bonding in (C20H20P)2SbCl5·(EA) resulting in strong interactions between the organic and inorganic components, good mobility, and improved exciton utilization. This study introduces a rational strategy for microstructure optimization, which builds upon solvent modulation to achieve stronger hydrogen bonding and thus improve the PLQY of 0D OIMHs.