Optical Functional Units in Zero‐Dimensional Metal Halides as a Paradigm of Tunable Photoluminescence and Multicomponent Chromophores

Abstract Zero‐dimensional (0D) organic–inorganic hybrid luminescent metal halides have many promising optoelectronic applications; however, the single building unit in the 0D framework restricts their multimode optical control and photoluminescence tuning. Thus, it remains urgent but challenging to rationally design distinct anionic polyhedral with different optical functions and further expand this family by an equivalent cation substitution and halogen replacement. Herein, (C₉NH₂₀)₉[Pb₃X₁₁](MX₄)₂ (X = Br and Cl, M = Mn, Fe, Co, Ni, Cu, and Zn) is successfully synthesized verifying the rationality of the design philosophy, and the optical characterizations demonstrate the effects of X‐position anions and M‐position cations on luminescence process. Intriguingly, both [Pb₃X₁₁]⁵⁻ and [MX₄]²⁻ perform as inorganic building units in this 0D system and optically active centers, in which the former leads to high‐efficiency broad‐band yellow/green emission originating from self‐trapped excitons and the as‐observed multicomponent chromophores are derived from the absorption of the latter in the visible light region. The present work highlights the importance of different optical functional units showing synergistic effects on the physical properties and inspires future studies to explore multifunctional application of 0D luminescent metal halides.