Colloidal CsPbBr3 perovskite nanocrystal films as electrochemiluminescence emitters in aqueous solutions

Perovskite nanocrystals (NCs), which have emerged as a new class of phosphors with superb luminescence properties and bandgaps that can be easily tuned using chemical methods, have generated tremendous interest for a wide variety of applications where colloidal quantum dots have been very successful as carrier sources. In this study, self-assembled films of CsPbBr 3 NCs were produced via drop casting of colloidal NCs onto glassy carbon electrodes (GCEs) to form an NC film-modified electrode. The possible fabrication process of the CsPbBr 3 NCs films was discussed. We further studied the anodic electrochemiluminescence (ECL) behavior of the perovskite CsPbBr 3 NCs film using cyclic voltammetry with tripropylamine (TPA) as a coreactant, and a possible ECL mechanism was proposed. Briefly, TPA was oxidized to produce strongly reducing radical species, which can react with electrochemically oxidized CsPbBr 3 NCs to generate excited CsPbBr 3 NCs* capable of light emission. The relative stability of the ECL emission of the CsPbBr 3 NC films under aqueous conditions was also investigated, and it was found that they showed operational stability over the first three hours, indicating suitable reliability for application as sensing materials. The results suggested that semiconducting perovskite NCs have great potential for application in the ECL field.