Sustainable and Self‐Enhanced Electrochemiluminescent Ternary Suprastructures Derived from CsPbBr3 Perovskite Quantum Dots

Abstract Lead halide perovskite quantum dots (QDs) are promising electrochemiluminescence (ECL) nanoemitters due to their fascinating photophysical properties. However, due to their poor structural stability against the external environment, the trade‐off between their colloidal stability and carrier injection/transport efficiency is a major challenge in the advancement of perovskite‐based ECL technology. In this work, intense and stable ECL from CsPbBr 3 (CPB) QDs is achieved by simultaneously encapsulating CPB QDs and coreactant (CoR) into in situ generated SiO 2 matrix via hydrolysis of tetramethyl orthosilicate. The well‐designed architecture of the as‐obtained CPB‐CoR@SiO 2 nanocomposites (NCs) guarantees not only greatly improved stability thanks to the peripheral SiO 2 protecting matrix, but also efficient self‐enhanced ECL between CPB and the intra‐coreactants. Consequently, by elaborately selecting the CoR molecules with different tertiary/secondary amines and functional groups, multifold higher (up to 10.2 times) ECL efficiencies are obtained for the CPB‐CoR@SiO 2 NCs alone in reference to the standard Ru(bpy) 3 2+ /tri‐ n ‐propylamine system. This work provides an efficient design strategy for obtaining stable and highly efficient ECL from perovskite QDs, and offers a new perspective for the development and application of perovskite‐based ECL system.