Space‐confined growth of CsPbBr₃ nanocrystals in mesoporous KIT‐6 and application in LEDs

Abstract

All‐inorganic CsPbX3 (X = Cl, Br, and I) perovskite nanocrystals (NCs) have great application prospects in many fields due to their excellent photoelectric properties. However, CsPbX3 NCs are extremely sensitive to water, heat, light, and oxygen, which leads to dramatic photoluminescence quenching and seriously restricts their future commercial applications. Herein, a novel, simple one‐step solution strategy for synthesizing high‐quality CsPbBr3 NCs was reported. By the combination of the hot‐injection process with the mesoporous template confinement effect of the KIT‐6 matrix, the space‐confined growth of NCs was precisely achieved. The CsPbBr3 NCs encapsulated by KIT‐6 (CsPbBr3@KIT‐6 composite) exhibited a uniform size, a high photoluminescence quantum yield (PLQY) of up to 82%, and a narrow full width at half‐maximum (FWHM) of 24 nm. Most importantly, CsPbBr3@KIT‐6 powder composites had dramatically enhanced light, thermal and water stability in comparison with colloidal CsPbBr3 NCs due to the dual protection of organic ligands and matrix templates. Ultimately, a white light‐emitting diode (LED) device was successfully fabricated by encapsulating a mixture of green‐emitting CsPbBr3@KIT‐6 composite and red‐emitting K2SiF6:Mn4+ phosphor onto a blue‐emitting InGaN LED chip. A color coordinate of (0.327, 0.337) and a wide color gamut of 128% NTSC well demonstrate their potential applications in lighting and display.

Advanced lead-free double perovskites/silica hybrid nanocrystals for highly stable light-emitting diodes

“…43 Combining the enhanced elemental binding energy of the lead-free DP NCs in Cs 2 AgIn 0.98 Bi 0.02 Cl 6 @KIT-6, it can be concluded that the binding of the Cs 2 AgIn 0.98 Bi 0.02 Cl 6 NCs and the KIT-6 shell layer should belong to strong chemical bonding rather than simple physical adsorption. 44 Of these, the KIT-6 mesoporous molecular sieves provided better passivation and space-confined growth templates for the Cs 2 AgIn 0.98 Bi 0.02 Cl 6 NCs, so that Cs 2 AgIn 0.98 Bi 0.02 Cl 6 @KIT-6 NCs should possess superior PL properties and enhanced stability.…”

CsPbBr3 Nanorod Luminescent Property Study

“…They mixed CsBr, PbBr 2 , oleylamine, and oleic acid in butanol solvent, followed by ultrasonication to form CsPbBr 3 nanorods . Analyzing previous studies, it is evident that halting the growth of perovskite crystals during their early stages presents a significant challenge, − making the direct synthesis of NRs very difficult.…”