In-situ spectroelectrochemical analysis: Irreversible deformation of cesium lead bromide Perovskite Quantum Dots in SiOx matrices

To practically utilized the organometallic lead halide perovskites to optoelectronic devices and photoelectrochemical cells, numerous efforts have been utilized to obtain the perovskites with low-energy process with coverage of various inorganic mediums to improve stability against humidity. By utilizing ligand-assisted reprecipitation process, under ambient condition at room temperature, the dimensionally confined perovskite quantum dots in silica matrices (PQD@SiO_x) were obtained, and they were stable under several months under the ambient condition. To apply the PQD@SiO_x to the photoelectrochemical cells by introducing direct contact between PQD@SiO_x and electrolyte, the material/photophysical properties under electrochemical conditions are necessary to be studied. However, the role of silica coverage to the electrochemical behaviors of the PQD cores in the silica medium were not yet studied. In this work, under the electrochemical conditions, the oxidative and reductive behaviors of the PQD@SiO_x were studied. Also, through in-situ spectroelectrochemical study, the electrochemically induced irreversible deformation process were tracked. The findings of this study could be used to understand role of silica coverage and develop the strategy to improve the protecting behavior of the silica for the PQD cores to utilize into the photoelectrochemical cells.