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

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 (C6N2H16)SbCl5 (I) to (C6N2H16)SbCl5⋅H2O (II) by introducing H2O molecules. These two compounds have very similar inorganic frameworks, except that the incorporation of water molecules in II increases the distance between the [SbCl5] 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. Two new Sb‐based 0D organic–inorganic metal halides, (C6N2H16)SbCl5 (I) and (C6N2H16)SbCl5⋅H2O (II) are obtained. They have similar luminous characteristics yet a different photoluminescence quantum yield (PLQY), achieving a 57% increase. Theoretical calculation indicates the impact of localized photoelectrons to PLQY. This work provides a key idea for designing 0D organic–inorganic metal halide hybrids with high PLQY.