Enhancing Photoluminescence Quantum Yield in 0D Metal Halides by Introducing Water Molecules

Abstract Enhancing photoluminescence quantum yield (PLQY) is one of the most important issues in photoluminescent materials. Herein, a molecule design strategy to improve the PLQY in 0D metal halides is proposed. Two new lead‐free organic–inorganic metal halide hybrids with broadband orange emissions have been prepared with a PLQY increase of 57% from (C 6 N 2 H 16 )SbCl 5 ( I ) to (C 6 N 2 H 16 )SbCl 5 ⋅H 2 O ( II ) by introducing H 2 O molecules. These two compounds have very similar inorganic frameworks, except that the incorporation of water molecules in II increases the distance between the [SbCl 5 ] polyhedra. It is revealed that the increase of PLQY is mainly attributed to the generation of more local photoelectrons resulting from the additional water molecules. This work provides a new insight to improve the PLQY for 0D environmentally friendly organic–inorganic metal halide hybrids and is beneficial for further photoluminescent material exploration.