Hydrogen Peroxide Involved Anodic Charge Transfer and Electrochemiluminescence of All-Inorganic Halide Perovskite CsPbBr₃ Nanocrystals in an Aqueous Medium

Abstract

Reactive oxygen species (ROS) involved anodic charge transfer and electrochemiluminescence (ECL) of all-inorganic halide perovskite CsPbBr₃ nanocrystals (NCs) were investigated in an aqueous medium with hydrogen peroxide (H₂O₂) as the model. CsPbBr₃ NCs could be electrochemically oxidized to positively charged states by injecting holes onto the highest occupied molecular orbitals and could be chemically reduced to negatively charged states by injecting electrons onto the lowest unoccupied molecular orbitals by ROS. The charge transfer between CsPbBr₃ NCs of oxidative and reductive states could bring out monochromatic ECL with onset around +0.8 V, maximum emission around 519 nm, and a full width at half-maximum around 20 nm. H₂O₂ could selectively enhance the anodic ECL of CsPbBr₃ NCs, which not only opened a way to design a bioprocess-involved photovoltaic device with CsPbBr₃ NCs but also was promising for color-selective ECL biosensing.