Chemiluminescence of CsPbBr₃ Perovskite Nanocrystal on the Hexane/Water Interface

All-inorganic halide perovskite CsPbBr₃ nanocrystals (NCs) have attracted more attention in recent years due to the unique optical feature. To date, most of the research was mainly focused on the photoluminescence (PL) and electrochemiluminescence (ECL) of the perovskite NCs. In this work, the strong chemiluminescence (CL) emission of CsPbBr₃ NCs was observed for the first time on the hexane/water interface with the assistance of ammonium persulfate-(NH₄)₂S₂O₈ as coreactant. Different coreactants were investigated to demonstrate the effect on the CL behavior and it was found that CL intensity achieved the maximum in the presence of (NH₄)₂S₂O₈. In this system, electron transfer took place on the surface of the CsPbBr₃ NCs, and the excited CsPbBr₃ NCs was originated from the direct chemical oxidation of (NH₄)₂S₂O₈. The CL spectrum of CsPbBr₃ NCs was also collected and was consistent with their PL and ECL spectra, indicating that CsPbBr₃ NCs played a role of luminophor during the CL process. The discovery of monochromatic CL of highly crystallized CsPbBr₃ NCs not only extends the applications of halide perovskite materials in the analytical field but also provides a new route for the exploration of the physical chemistry properties.