Water-resistant, monodispersed and stably luminescent CsPbBr₃/CsPb₂Br₅ core–shell-like structure lead halide perovskite nanocrystals

Abstract

Lead halide perovskite materials are thriving in optoelectronic applications due to their excellent properties, while their instability due to the fact that they are easily hydrolyzed is still a bottleneck for their potential application. In this work, water-resistant, monodispersed and stably luminescent cesium lead bromine perovskite nanocrystals coated with CsPbBr were obtained using a modified non-stoichiometric solution-phase method. CsPbBr 2D layers were coated on the surface of CsPbBr nanocrystals and formed a core-shell-like structure in the synthetic processes. The stability of the luminescence of the CsPbBr nanocrystals in water and ethanol atmosphere was greatly enhanced by the photoluminescence-inactive CsPbBr coating with a wide bandgap. The water-stable enhanced nanocrystals are suitable for long-term stable optoelectronic applications in the atmosphere.

Photoluminescence Mechanisms of All‐Inorganic Cesium Lead Bromide Perovskites Revealed by Single Particle Spectroscopy

“…Based on the DFT calculations, CsPb 2 Br 5 adopts an indirect bandgap of 3.1 eV (Figure a), which is supposed to be PL inactive. This is consistent with some experimental results that no PL was observed from pure CsPb 2 Br 5 . The luminescence center of CsPb 2 Br 5 ‐related system is believed to arise from the secondary phase generated during the synthesis procedure.…”

“…CsPb 2 Br 5 has a tetragonal quasi‐2D structure at the room temperature . Compared with CsPbBr 3 , CsPb 2 Br 5 shows higher chemical stability . In a CsPb 2 Br 5 crystal, the quasi‐2D structure confines all the Pb 2+ and Br ‐ in [Pb 2 Br 5 ] − layer.…”

“…[12a,38] Compared with CsPbBr 3 , CsPb 2 Br 5 shows higher chemical stability. [39] In a CsPb 2 Br 5 crystal, the quasi-2D structure confines all the Pb 2 + and Brin [Pb 2 Br 5 ] À layer. Each [Pb 2 Br 5 ] À coordination polyhedron layer is intercalated by one layer of Cs ions.…”

“…This is consistent with some experimental results that no PL was observed from pure CsPb 2 Br 5 . [39][40][41] The luminescence center of CsPb 2 Br 5 -related system is believed to arise from the secondary phase generated during the synthesis procedure. In stark contrast, green emission of pure CsPb 2 Br 5 has also been observed in some other reports.…”

Effects of Iodine Doping on Carrier Behavior at the Interface of Perovskite Crystals: Efficiency and Stability

“…Organometal halide perovskite solar cells (PSCs) have attracted much attention because of their advantages such as high-power efficiency [1][2][3], flexibility [4][5][6], and long-term stability [7][8][9]. Compared with silicon solar cells [10][11][12], perovskite solar cells have simplified manufacture processing, and can be rapidly fabricated by spin-coating with precursor solutions of lead (II) iodide and methylamine hydroiodide (MAI).…”