Lead‐Free, Blue Emitting Bismuth Halide Perovskite Quantum Dots

Abstract

Lead halide perovskite quantum dots (QDs) are promising candidates for future lighting applications,d ue to their high quantum yield, narrow full width at half maximum (FWHM), and wide color gamut. However,the toxicity of lead represents ap otential obstacle to their utilization. Although tin(II) has been used to replace lead in films and QDs,the high intrinsic defect density and oxidation vulnerability typically leads to unsatisfactory material properties.Bismuth, with much lower toxicity than lead, is promising to constitute lead-free perovskite materials because Bi 3+ is isoelectronic to Pb 2+ and more stable than Sn 2+ .Herein we report, for the first time,the synthesis and optical characterization of MA 3 Bi 2 Br 9 perovskite QDs with photoluminescence quantum yield (PLQY) up to 12 %, whichi sm uchh igher than Sn-based perovskite nanocrystals.F urthermore,t he photoluminescence (PL) peaks of MA 3 Bi 2 X 9 QDs could be easily tuned from 360 to 540 nm through anion exchange.

Recent advances and prospects toward blue perovskite materials and light‐emitting diodes

“…More specifically, mixed‐Cl/Br perovskites tend to demonstrate a red shift because of electrical‐field‐induced phase segregation, and 2D perovskite NCs face the risk of grain growth. Besides the regulation of A‐ and X‐site, B‐site doping, and lead‐free perovskites can also achieve blue emission, yet lack of application on LED devices. It is worth mentioning that the stability of the blue perovskite QDs can be improved by the B‐site atom treatment .…”

“…Once the lead and its compounds pollute the soil or water, the damage to the soil and all organisms is almost eternal due to its long degradation lifetime, and stability in the Pb ecosystem. Due to these factors, Bi‐, Sn‐, and Sb‐based lead‐free perovskites have become promising alternatives to construct blue emissive materials …”

Efficient and Stable CsPb(Br/I)3@Anthracene Composites for White Light-Emitting Devices

“…16,20 However, the anion-exchange reaction between different halide inorganic perovskites on the other hand limits their application in white light-emitting devices (WLEDs). 18,19,21,22 …”

Reversible Ultra‐Slow Crystal Growth of Mixed Lead Bismuth Perovskite Nanocrystals: The Presence of Dynamic Capping

“…[8] Recently scientists have startedt o explore Pb-free perovskites with variousc ations at the B-site. [11] Therefore, it is ap rimary concernt os earch for as ystem with high quantum yield withoutc ompromising stability. [10] However,the quantum yield of these Bi-basedp erovskite NCs is very low.…”