posted on 2022-12-19, 14:36authored byCarlos Romero-Pérez, Andrea Zanetta, Natalia Fernández-Delgado, Miriam Herrera-Collado, Jesús Hernández-Saz, Sergio Ignacio Molina, Laura Caliò, Mauricio E. Calvo, Hernán Míguez
Herein we show that dispersing inorganic cesium lead
bromide (CsPbBr3) perovskite quantum dots (QDs) in optical
quality films,
possessing an accessible and controlled pore size distribution, gives
rise to fluorescent materials with a controlled and highly sensitive
response to ambient changes. A scaffold-based synthesis approach is
employed to obtain ligand-free QDs, whose pristine surface endows
them with high sensitivity to the presence of different vapors in
their vicinity. At the same time, the void network of the host offers
a means to gradually expose the embedded QDs to such vapors. Under
these conditions, the luminescent response of the QDs is mediated
by the mesostructure of the matrix, which determines the rate at which
vapor molecules will adsorb onto the pore walls and, eventually, condensate,
filling the void space. With luminescence quantum yields as high as
60%, scaffold-supported ligand-free perovskite nanocrystals display
intense photoemission signals over the whole process, as well as high
photo- and chemical stability, which allows illuminating them for
long periods of time and recovering the original response upon desorption
of the condensed phase. The results herein presented open a new route
to explore the application of perovskite QD-based materials in sensing.