Lead‐Free, Blue Emitting Bismuth Halide Perovskite Quantum Dots

Abstract

Lead halide perovskite quantum dots (QDs) are promising candidates for future lighting applications, due to their high quantum yield, narrow full width at half maximum (FWHM), and wide color gamut. However, the toxicity of lead represents a potential 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 is isoelectronic to Pb and more stable than Sn . Herein we report, for the first time, the synthesis and optical characterization of MA Bi Br perovskite QDs with photoluminescence quantum yield (PLQY) up to 12 %, which is much higher than Sn-based perovskite nanocrystals. Furthermore, the photoluminescence (PL) peaks of MA Bi X QDs could be easily tuned from 360 to 540 nm through anion exchange.

Carrier Interfacial Engineering by Bismuth Modification for Efficient and Thermoresistant Perovskite Solar Cells

“…FA 0.83 MA 0.17 Pb(I 0.83 Br 0.17 ) 3 perovskite precursor was synthesized through formamidinium iodide (FAI), PbI 2 , MABr, and PbBr 2 in dimethylformamide (DMF) and dimethyl sulfoxide (DMSO) mixture solution (4:1 volume ratio), according to the typical method. [15] For the doped MB x films, the diffraction patterns are in good agreement with that of the trigonal perovskite structure (P3m1). FA 0.83 MA 0.17 Pb(I 0.83 Br 0.17 ) 3 was used as the control perovskite photoactive material.…”

“…The PSC fabrication process is based on our previous method. [15] The coexistence of Pb, Bi, I, and Br elements in MB 1.5 is confirmed by energy dispersive spectroscopy (EDS) mapping technique ( Figure S2, Supporting Information). XRD measurements show that the MA 3 Bi 2 Br 9 films exhibit the characteristic peaks at 17.7°, 26.6°, 45.1°, and 54.8° with trigonal P3m1 symmetry, which is fully consistent with previous reports.…”

Halide Perovskite Nanocrystals for Next‐Generation Optoelectronics

“…Ternary metal‐halide materials including a trivalent metal ion (bismuth, Bi 3+ ), with similar electronic properties (because of the same 6s2 configuration) as Pb, have A 3 Bi 2 X 9 configuration, e.g., (CH 3 NH 3 ) 3 Bi 2 X 9 or Cs 3 Bi 2 X 9 . Antimony (Sb) is another element with low toxicity, belonging to the same column with Bi in the periodic table.…”

Charge Transport between Coupling Colloidal Perovskite Quantum Dots Assisted by Functional Conjugated Ligands

“…[20][21][22][23][24] Fora nother,a ll of these QD applications require efficient carrier injection and transport in QDs films. [20][21][22][23][24] Fora nother,a ll of these QD applications require efficient carrier injection and transport in QDs films.…”