Open AccessUniversal Size-Dependent Stokes Shifts in Lead Halide Perovskite Nanocrystals
Author(s) -
Michael C. Brennan,
Aaron Forde,
Maksym Zhukovskyi,
Andrew J. Baublis,
Yurii V. Morozov,
Shubin Zhang,
Zhuoming Zhang,
Dmitri S. Kilin,
Masaru Kuno
Publication year - 2020
Publication title -
the journal of physical chemistry letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.563
H-Index - 203
ISSN - 1948-7185
DOI - 10.1021/acs.jpclett.0c01407
Subject(s) - nanocrystal , perovskite (structure) , halide , stokes shift , photoluminescence , picosecond , polaron , materials science , length scale , chemical physics , chemistry , crystallography , physics , nanotechnology , luminescence , optics , optoelectronics , inorganic chemistry , quantum mechanics , laser , electron
Size-dependent photoluminescence Stokes shifts (Δ E s ) universally exist in CsPbX 3 (X = Cl - , Br - , or I - ) perovskite nanocrystals (NCs). Δ E s values, which range from ∼15 to 100 meV for NCs with average edge lengths ( l ) from approximately 13 to 3 nm, are halide-dependent such that Δ E s (CsPbI 3 ) > Δ E s (CsPbBr 3 ) ≳ Δ E s (CsPbCl 3 ). Observed size-dependent Stokes shifts are not artifacts of ensemble size distributions as demonstrated through measurements of single CsPbBr 3 NC Stokes shifts (⟨Δ E s ⟩ = 42 ± 5 meV), which are in near quantitative agreement with associated ensemble ( l = 6.8 ± 0.8 nm) Δ E s values (Δ E s ≈ 50 meV). Transient differential absorption measurements additionally illustrate no significant spectral dynamics on the picosecond time scale that would contribute to Δ E s . This excludes polaron formation as being responsible for Δ E s . Altogether, the results point to an origin for Δ E s , intrinsic to the size-dependent electronic properties of individual perovskite NCs.
Accelerating Research
Robert Robinson Avenue,
Oxford Science Park, Oxford
OX4 4GP, United Kingdom
Address
John Eccles HouseRobert Robinson Avenue,
Oxford Science Park, Oxford
OX4 4GP, United Kingdom