2024/03/13 by Carlos Romero‐Pérez, Romero-Perez, Carlos, Natalia Fernandez Delgado +6
Engineering · #Applied Physics (physics.app-ph) #FOS: Physical sciences #Materials Science (cond-mat.mtrl-sci) #Perovskite Materials and Applications
paper · doi:10.48550/arxiv.2403.08315
openalex publication_date 2024/03/13 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
Lead halide perovskite nanocrystals are attractive for light emitting devices both as electroluminescent and color converting materials, since they combine intense and narrow emissions with good charge injection and transport properties. However, most perovskite nanocrystals shine at green and red wavelengths, the observation of intense and stable blue emission still being a challenging target. In this work, we report a method to attain intense and enduring blue emission (470-480 nm), with a photoluminescence quantum yield (PLQY) of 40%, originated from very small CsPbBr3 nanocrystals (diameter<3nm) formed by controllably exposing Cs4PbBr6 to humidity. This process is mediated by the void network of a mesoporous transparent scaffold in which the zero-dimensional (0D) Cs4PbBr6 lattice is embedded, which allows the fine control over water adsorption and condensation that determines the optimization of the synthetic procedure and, eventually, the nanocrystal size. By temperature dependent photoemission analysis of samples with different [CsPbBr3]/[Cs4PbBr6] volume ratios, we show that the bright blue emission observed results from the efficient charge transfer to the CsPbBr3 inclusions from the Cs4PbBr6 host. Our approach provides a means to attain highly efficient transparent blue light emitting films that complete the palette offered by perovskite nanocrystals for lighting and display applications.