Huaiyu Chen
Profile area member
Sinusoidal Displacement Describes Disorder in CsPbBr3 Nanocrystal Superlattices
Author
Summary, in English
Disorder is an intrinsic feature of all solids, from crystals of atoms
to superlattices of colloidal nanoparticles. Unlike atomic crystals, in
nanocrystal superlattices, a single misplaced particle can affect the
positions of neighbors over long distances, leading to cumulative
disorder. This elusive form of collective particle displacement leaves
clear signatures in diffraction, but little is known about how it
accumulates and propagates throughout the superlattice. Here we
rationalize the propagation and accumulation of disorder in a series of
CsPbBr3 nanocrystal superlattices by using synchrotron grazing incidence small- and wide-angle X-ray scattering. CsPbBr3 nanocrystals of colloidal softness S
in the range of 0.3–0.7 were obtained by preparing particles with
different sizes and ligand mixtures consisting of oleic acid and primary
amines of variable lengths. Most diffraction patterns showed clear
signatures of anisotropic disorder, with multilayer diffraction
characteristics of high structural coherence visible only for the {100}
axial directions and lost in all other directions. As the softness
decreased, the superlattices transitioned to a more ordered regime where
small-angle diffraction peaks became resolution-limited, and
superlattice multilayer diffraction appeared for the (110) diagonal
reflections. To rationalize these anisotropies in structural coherence
and their dependence on superlattice softness, we propose a sinusoidal
displacement model where longitudinal and transverse displacements
modulate nanocrystal positions. The model explains experimental
observations and advances the understanding of disorder in
mesocrystalline systems as they approach the limits of structural
perfection.
to superlattices of colloidal nanoparticles. Unlike atomic crystals, in
nanocrystal superlattices, a single misplaced particle can affect the
positions of neighbors over long distances, leading to cumulative
disorder. This elusive form of collective particle displacement leaves
clear signatures in diffraction, but little is known about how it
accumulates and propagates throughout the superlattice. Here we
rationalize the propagation and accumulation of disorder in a series of
CsPbBr3 nanocrystal superlattices by using synchrotron grazing incidence small- and wide-angle X-ray scattering. CsPbBr3 nanocrystals of colloidal softness S
in the range of 0.3–0.7 were obtained by preparing particles with
different sizes and ligand mixtures consisting of oleic acid and primary
amines of variable lengths. Most diffraction patterns showed clear
signatures of anisotropic disorder, with multilayer diffraction
characteristics of high structural coherence visible only for the {100}
axial directions and lost in all other directions. As the softness
decreased, the superlattices transitioned to a more ordered regime where
small-angle diffraction peaks became resolution-limited, and
superlattice multilayer diffraction appeared for the (110) diagonal
reflections. To rationalize these anisotropies in structural coherence
and their dependence on superlattice softness, we propose a sinusoidal
displacement model where longitudinal and transverse displacements
modulate nanocrystal positions. The model explains experimental
observations and advances the understanding of disorder in
mesocrystalline systems as they approach the limits of structural
perfection.
Department/s
- Chemical Physics
- NanoLund: Centre for Nanoscience
- LTH Profile Area: Nanoscience and Semiconductor Technology
- LU Profile Area: Light and Materials
- LTH Profile Area: Photon Science and Technology
- Lund Laser Centre, LLC
- MAX IV, Science division
- Synchrotron Radiation Research
- eSSENCE: The e-Science Collaboration
- MAX IV Laboratory
Publishing year
2026-02-03
Language
English
Pages
3867-3877
Publication/Series
ACS Nano
Volume
20
Issue
4
Document type
Journal article
Publisher
The American Chemical Society (ACS)
Topic
- Nano-technology
- Materials Chemistry
- Condensed Matter Physics (including Material Physics, Nano Physics)
Status
Published
Project
- Engineering of Superfluorescent Nanocrystal Solids
- Superlattices of Perovskite Quantum-Dots for the Digital-age
- eSSENCE@LU 8:2 - Coherent 3D X-ray imaging of nanoparticles with unknown orientation
- High resolution X-ray detectors based on nanowire arrays
- Heterostructured metal halide perovskite nanowires
ISBN/ISSN/Other
- ISSN: 1936-086X