The instability of lead halide perovskites (LHPs) has tremendously hindered their practical applications. Although some examples on encapsulating LHPs into a SiO2 shell have been reported, these SiO2-coated LHPs still suffer from limited stability. Herein, MAPbBr3 (MA = CH3NH3 +) nanoparticles encapsulated in double hydrophobic shells of organic functionalized SiO2 and poly­(vinylidene fluoride) (MAPbBr3@SiO2/PVDF) are successfully synthesized by infiltrating the MAPbBr3 precursor solution into hollow siliceous nanospheres and followed by PVDF capping. With the dual protection of SiO2 and PVDF, the MAPbBr3@SiO2/PVDF nanoparticles exhibit drastically improved stability against water and UV-light illumination. A white light-emitting diode with luminous efficiency up to 147.5 lm W–1 and a color gamut encompassing 120% of National Television System Committee in Commission Internationale de L’Eclairage 1931 color space has been demonstrated using the MAPbBr3@SiO2/PVDF nanoparticles as the green light source. This study enlightens new insights into the synthesis of highly stable LHPs-based core–shell–shell architectures toward their practical applications.

The design of photoluminescence-quenching probes for molecular oxygen (O) is always a large space to explore. Luminescent semiconductor nanocrystals (NCs) have been proposed as emerging oxygen-responsive probes, but the inherent O sensing of phosphorescent semiconductor NCs has not been reported so far. Here, we demonstrate the O sensing capability of Mn-doped CsPbCl nanocrystals (Mn:CsPbCl NCs) and reveal the role of O on the optical de-excitation process of such perovskite nanocrystals (PNCs). By adjusting the amount and distribution of Mn dopants, as well as the host-dopant energy transfer process in PNCs, we highlight that O can reversibly quench the Mn emission due to the temporary disturbance to the ligand field of near-surface Mn dopants in PNCs. In phosphorescence mode, the photoluminescence intensity of the Mn:CsPbCl NCs is quenched by 53% on increasing O concentration from 0 to 100%. The Stern-Volmer plot shows a good linear in the 0-12% O concentration range. High sensing reversibility and rapid signal response are also achieved. In our perception, the mechanism study makes our PNCs candidates for the optical probes of O, and it is enlightening to explore more possibilities of the inherent O sensing based on the semiconductor-doped NCs (not restricted to Mn-doped PNCs) with phosphorescence emission.

Herein, a three-phase heterostructure interface including glassy carbon, CsPbBr3 perovskite nanocrystals and acetonitrile is constructed for fully investigating the interfacial electrochemiluminescence (ECL) behavior of CsPbBr3 PNCs.

Low-dimensional (LD) organic-metal halides (OMHs) have been extensively investigated because of their excellent optical properties. However, the rational synthetic control (dimension regulation) of LD-OMHs has not yet been established well. The effect of organic cations on the luminescence also remains unexplored. Here, we designed a double-chain ammonium salt 1 with two amine functional groups. Using hydrogen bonding between −N−H 3 protons and halogen ions synthesized zero-dimensional (0D) OMH C 12 H 30 N 4 Pb 2 Br 8 (2). Furthermore, through introducing other ionic interactions to regulate the dimension of OMHs, we obtained onedimensional (1D) OMH C 12 H 30 N 4 Pb 2 Cl 7.5 Br 0.5 (3) by anion exchange of 2. Through the in-depth analysis of their crystal structure, it is understood that the design of organic cations and the exchange of anions can regulate the dimension of OMHs through the change of hydrogen bonds in the structure. This sets a foundation for the formation of a synthesis mechanism for LD-OMHs and effective regulation of OMHs dimension. Through crystal structure analysis, experiments, and theoretical calculations, this work proves that the emission of 2 is not dominated by a single factor of organic cations or metal halogen octahedrons but by the interaction of organic cations and metal octahedrons. Moreover, the 1D-OMH 3 shows tunable emissions from blue to white light under varying excitation wavelengths, which provides a foundation for expanding the application of OMHs.

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