Insulating CsPbBr3 Quantum Dots via Encapsulation with SiOx: Interfacial Electron Trafficking and Interaction beyond the Insulating Boundary

Abstract

Dense and long-chain ligands on the surface of lead halide perovskite quantum dots (PQDs) hinder charge transport. Thus, it is extremely challenging to achieve environmentally stable PQDs with an appropriate ligand, optimal density, and successful charge transfer to charge acceptors. Through comprehensive material development and photo-physical experiments, rapid crystallization of CsPbBr3 PQDs encapsulated in crude silica shells at room temperature was achieved using (3-aminopropyl)triethoxysilane as the key coordinating ligand. Following the control post-annealing treatment, highly stable PQDs wrapped in robust insulating silica shells were obtained; they exhibited phenomenal electron transfer characteristics beyond silica shell coverage. Based on the electron transfer phenomenon from the core-shell PQDs to the electron transport media, the formation of photoinduced superoxide ions was demonstrated. These ions triggered the photocatalytic degradation of 2-mercaptobenzothiazole. This study presents advanced insights into core-shell CsPbBr3 PQDs covered in silica shells and their detailed photochemistry for renewable energy applications.