Lead‐Free, Luminescent Perovskite Nanocrystals Obtained through Ambient Condition Synthesis

Abstract

Heterovalently substituting toxic lead is an increasingly popular design strategy to obtain environmentally sustainable variants of the exciting material class of halide perovskites. Perovskite nanocrystals (NCs) obtained through solution‐based methods exhibit exceedingly high optical quality. Unfortunately, most of these synthesis routes still require reaction under inert gas and at very high temperatures. Herein a novel synthesis routine for lead‐free double perovskite (LFDP) NCs is presented. An approach based upon the hot injection and ligand‐assisted reprecipitation (LARP) methods to achieve a low‐temperature and ambient atmosphere‐based synthesis for manganese‐doped Cs2NaBiCl6 NCs is presented. Mn incorporation is critical for the otherwise non‐emissive material, with a 9:1 Bi:Mn precursor ratio maximizing the bright orange photoluminescence (PL) and quantum yield (QY). Higher synthesis temperatures slightly increase the material's performance, yet NCs synthesized at room temperature are still emissive, highlighting the versatility of the synthetic approach. While the material's indirect bandgap limits its appeal for optoelectronics, this feature could benefit photocatalysis due to longer carrier lifetimes. Moreover, the developed synthesis is facile and can rapidly be adapted to other more viable material compositions and up‐scaled to realize applications directly.

Recent advance of high-quality perovskite nanostructure and its application in flexible photodetectors

“…Initially, the perovskite precursors were dissolved in a toluene solvent, followed by the injection of trimethylsilylchloride (TMSCl) to initiate the formation of perovskite NCs under a constant temperature. Moreover, the Mn:Cs 2 NaBiCl 6 NCs exhibited a bright orange PL with a peak at 595 nm, originating from the d-d transition of the Mn 2+ dopant [80]. In summary, the LARP method offers a facile pathway for the large-scale production of high-performance perovskite NCs.…”

Perovskite Paradigm Shift: A Green Revolution with Lead-Free Alternatives in Photocatalytic CO2 Reduction

“…173−176 The size of LFHP crystals is tunable by varying the temperature at which LARP is performed. 177,178 In the synthesis of Cs 3 Sb 2 Br 9 via LARP, the precursor solution was injected into the nonpolar solvent at various low reaction temperatures of 30, 50, and 70 °C, in which a high temperature led to uneven particle size distribution with lower photocatalytic activity. 178 On the other hand, Cs 2 NaBiCl 6 nanocrystals prepared at different temperatures (room temperature, 55, 70, 100, 115 °C) were comparable, with a slight increase in absorption and emission intensity for increasing temperature.…”

Ultralong Red Room-Temperature Phosphorescence of 2D Organic–Inorganic Metal Halide Perovskites for Afterglow Red LEDs and X-ray Scintillation Applications

“…Room-temperature phosphorescence (RTP) materials have found wide-ranging applications in fields such as organic optoelectronics, safety encryption, chemical sensors, display technology, and bioimaging. These materials possess the unique ability to store multiple radiations, including visible photons, ultraviolet light, and even X-rays, thanks to their long-lived triplet states and extended exciton-transfer distances. – Among the diverse range of RTP materials emitting at different wavelengths, red RTP materials play a crucial role in full-color displays, white-light lighting devices, and bioimaging applications. , Especially, they offer a high signal-to-background ratio, deep penetration depth, and minimal radiation damage to cells. , Consequently, there has been a growing interest in the design and synthesis of efficient red RTP materials in recent years . Common approaches to achieving this kind of materials include doping rare-earth-metal ions into inorganic hosts or utilizing triplet exciton-based spin-forbidden transitions by extending the π-conjugated system and incorporating donor–acceptor (D–A) structures in organic compounds. , However, the phosphors doped with rare-earth ions often suffer from low luminescence efficiency and poor stability against strong oxidants, ultraviolet radiation, or high temperatures .…”

“…1−3 Among the diverse range of RTP materials emitting at different wavelengths, red RTP materials play a crucial role in full-color displays, white-light lighting devices, and bioimaging applications. 4,5 Especially, they offer a high signal-to-background ratio, deep penetration depth, and minimal radiation damage to cells. 6,7 Consequently, there has been a growing interest in the design and synthesis of efficient red RTP materials in recent years.…”