Stable Lead-Free Cesium Tin Halide Double-Perovskite Nanocrystals Embedded in Polydimethylsiloxane for Candlelight Light-Emitting Diodes

Abstract

In this study, lead-free cesium tin halide (Cs 2 SnBr 6 ) double-perovskite nanocrystals (DPNCs) were synthesized and investigated using an easy hot-injection method. Hexagonal-shaped Cs 2 SnBr 6 DPNCs, having cubic symmetry with the Fm3̅ m space group, were exhibited for the first time through X-ray diffraction and Raman experiments. The bandgap structures and photoluminescence (PL) mechanism of self-trapped excitons in the Cs 2 SnBr 6 DPNCs were experimentally demonstrated by X-ray photoelectron and ultraviolet (UV)−visible absorption spectroscopy. The prepared Cs 2 SnBr 6 DPNCs had an average size of approximately 58 nm and generated orange emission at a wavelength of 600 nm (full-width at halfmaximum, 121 nm). These samples exhibited a PL quantum yield of approximately 31% and fluorescence lifetime of approximately 3.3 μs. The Cs 2 SnBr 6 DPNCs and blue phosphor (Sr 5 (PO 4 ) 3 Cl:Eu 2+ ) were mixed with polydimethylsiloxane packaging in 365 nm UV lightemitting diodes (LEDs), which were used to fabricate candlelight LEDs with a color-rendering index of 84 and a correlated color temperature of 2006 K. All these results can significantly contribute to the global use of low-toxicity and environmentally friendly luminescent materials for lighting sources.

Superstable CsxSnBrx+2@CsBr Nanocrystals with Over 1200 h of Half-Value PLQY in Air

“…To exclude the emission of Sn 4+ , the same hot-injection method was used in an attempt to synthesize Cs y Sn 4+ Br y+4 NCs, but the product failed to emit orange light, as shown in Figure S6d, which is the emission color of Cs y Sn 4+ Br y+4 NCs. 38 It is inferred that Cs y Sn 4+ Br y+4 has a high synthesis energy and cannot be synthesized by this method. Thus, it demonstrates that Sn 4+ , which is generated from the raw materials or during the synthesis process, did not contribute to the luminescence.…”

Impact of processing conditions on the film formation of lead-free halide double perovskite Cs2AgBiBr6

“…Apart from Cs 2 AgBiBr 6 , other halide double perovskites have been synthesized, including Cs 2 AgInCl 6 , Cs 2 AgBiCl 6 , Cs 2 SnI 6 , Cs 2 AgSbCl 6 , Cs 2 NaBiCl 6 , Cs 2 NaInCl 6 , Cs 2 SnBr 6 , Cs 2 SnCl 6 , Cs 2 -AgInBr 6 , Rb 2 AgInBr 6 , and Rb 2 CuInCl 6 . [36][37][38][39][40][41][42][43][44] The large share of Cs 2 AgBiBr 6 in experimental publications is probably due to the ease of processability of Cs 2 AgBiBr 6 from solutions due to the relatively good solubility of Cs 2 AgBiBr 6 precursors as compared to other halide double perovskite compounds. 7,8 Fig.…”

Recent Progress of Eco-friendly Lead-free Halide Perovskite Light-Emitting Diodes

“…[118] Sn 2+ 을 Sn 4+ 로 대체하 면 B자리에서 공공이 교대로 위치하면서 BX 6 팔면체 가 분리된 vacancy-ordered 이중 페로브스카이트를 형성할 수 있다. [119] Hot-injection 합성법으로 제조한 Copyright 2021, Wiley-VCH. [117] (c) Cs 2 SnBr 6 이중 페로브스카이트 NC의 hot-injection 합성법 과정 및 결정 구조.…”