Pith. sign in

REVIEW 4 major objections 4 minor 57 references

Direct observation of the exciton polaron by serial femtosecond crystallography on single CsPbBr$_3$ quantum dots

T0 review · 4 major / 4 minor · reviewed 2026-08-09 · deepseek-v4-flash

Challenge this review Re-run · record.json Download PDF Read on arXiv ↗

Pith's one-line read Resonant excitation of a single electron-hole pair distorts the lattice of a CsPbBr$_3$ quantum dot, forming an exciton polaron.

desk verdict A genuinely novel SFX experiment with a load-bearing statistical gap: the 3D difference maps need a null-hypothesis control before the exciton-polaron claim can stand. read the letter →

arxiv 2502.02343 v1 pith:GEQP2HT2 submitted 2025-02-04 cond-mat.mtrl-sci cond-mat.mes-hallphysics.data-an

Zhou Shen , Margarita Samoli , Onur Erdem , Johan Bielecki , Amit Kumar Samanta , Juncheng E , Armando Estillore , Chan Kim
show 23 more authors
Yoonhee Kim Jayanath Koliyadu Romain Letrun Federico Locardi Jannik Lübke Abhishek Mall Diogo Melo Grant Mills Safi Rafie-Zinedine Adam Round Tokushi Sato Raphael de Wijn Tamme Wollweber Lena Worbs Yulong Zhuang Adrian P. Mancuso Richard Bean Henry N. Chapman Jochen Küpper Ivan Infante Holger Lange Zeger Hens Kartik Ayyer
This is my paper · ORCID
classification cond-mat.mtrl-scicond-mat.mes-hallphysics.data-an PACS 71.38.-k78.67.Hc61.05.cp
keywords excitonpolaronCsPbBr3perovskitequantumdotsserialfemtosecondcrystallographydifferentialdiffractionlatticedeformationsinglelimitholelocalizationmixedlarge/small
verification ladder T0 review T1 audit T2 compute T3 formal

The pith

A machine-rendered reading of the paper's core claim, the machinery that carries it, and where it could break.

The reading

This paper reports the first direct structural observation of the lattice deformation caused by a single electron-hole pair in a perovskite quantum dot. The authors used serial femtosecond crystallography on individual 4.9 nm CsPbBr$_3$ quantum dots, comparing X-ray diffraction patterns recorded with and without resonant optical excitation, and reconstructed the three-dimensional difference pattern. They find that the Bragg peaks shift in a systematic radial pattern, which indicates a crystal-wide deformation rather than a mere change in atomic positions within the unit cell. Combining density-functional-theory relaxations with a model in which the hole localizes at a surface-biased random position while the electron stays delocalized, they identify the distortion as an exciton polaron of mixed large/small character. If correct, this provides the missing experimental picture of polaronic deformation behind the optoelectronic properties of lead halide perovskites.

What carries the argument

The load-bearing machinery is the three-dimensional differential diffraction map: each indexed single-dot snapshot is rotated and merged into reciprocal space, and the pumped minus unpumped maps expose shifts of the Bragg peaks, not just changes in their integrated intensity. The companion model is the random hole localization model, in which each pumped dot has a hole placed at a random, surface-biased position within the nanocrystal and every atom is displaced along the local electric field with a species-dependent restoring-force constant. What carries the argument is the connection between reciprocal-space peak shifts and the real-space displacement field: an inward shift of the 200 peak combined with an outward shift of the 110 peak is reproduced only when the hole is biased toward the surface and the bromine atoms are more weakly restrained than the cations.

What would settle it

Run the same serial crystallography measurement at half the pump fluence. The single-exciton model predicts the same shift pattern with proportionally fewer pumped dots; if the 200 and 110 shifts change sign or shape rather than simply scaling down, the deformation cannot be attributed to a single electron-hole pair. A complementary check is to shorten the pump-probe delay below the polaron formation time, in which case the peak shifts should disappear.

Watch

Extended reading notes

Core claim

The central claim is that resonant formation of one electron-hole pair in a 4.9 nm CsPbBr$_3$ quantum dot distorts the atomic lattice, i.e., creates an exciton polaron. The evidence is a light-on minus light-off three-dimensional diffraction map in which Bragg peaks shift slightly inward or outward, with the 200 peak shifting inward and the 110 peak outward. These shifts are only visible after orienting and merging single-dot diffraction snapshots in three dimensions; the azimuthally averaged powder patterns show no statistically significant difference. The radial pattern of shifts matches a longitudinal deformation field with cations displaced outward and anions inward, the field expected from a localized positive charge plus a delocalized negative charge. A model with the hole randomly localized but biased toward the dot surface reproduces the full shift pattern, whereas a central hole or a simple octahedral-tilt relaxation does not; the paper therefore concludes that the exciton polaron is a mixed large/small polaron with a delocalized electron and a surface-biased hole.

Load-bearing premise

The load-bearing premise is that the pumped frames really contain on average about one electron-hole pair per quantum dot, with roughly 75% of pumped dots in the single-exciton state and about 13% in the biexciton state, and that two pairs produce exactly twice the distortion of one pair; if the true excitation mix is different, the measured shifts would be misassigned to a single exciton polaron.

Editorial extensions

If this is right

  • A single electron-hole pair is enough to distort the whole lattice of a 4.9 nm quantum dot, so polaronic deformation does not require high excitation density.
  • The single-exciton distortion is qualitatively different from the octahedral-tilt relaxation commonly used to interpret multi-exciton experiments, because it produces peak shifts rather than only intensity changes.
  • The ensemble-averaged differential pattern is an average over dots with the hole at different positions, so the measured result contains statistical information about hole localization within individual dots.
  • Sweeping the pump-probe delay should make it possible to watch the polaron deformation build up and relax in reciprocal space with femtosecond time resolution.
  • For a homogeneous set of identical dots, the 3D difference pattern is directly related to the Fourier transform of the deformation field, potentially allowing the deformation to be mapped without a model.

Reading between the lines

Editorial extensions of the paper, not claims the author makes directly.

  • Beyond the paper, a fluence series would let one separate the zero-, one-, and two-pair subpopulations and test the assumption that two pairs double the single-pair distortion.
  • Beyond the paper, the surface bias of hole localization could be tested by comparing dots of different sizes: smaller dots, with a larger surface-to-volume ratio, should show a more pronounced outward 110 shift if the bias is surface-driven.
  • Beyond the paper, the same single-dot differential-diffraction protocol could be applied to other nanocrystals where polaron formation is debated, using the sign and direction of the peak shifts as a fingerprint of where the charge localizes.
  • Beyond the paper, the off-axis features in the difference map likely encode the distribution of hole positions and could constrain the localization statistics more tightly with a higher-quality dataset.
Share X Bluesky LinkedIn Reddit HN

Editorial analysis

A structured set of objections, weighed in public.

Desk editor's note, referee report, and a circularity audit.

Referee Report

4 major / 4 minor

Summary. The paper reports serial femtosecond crystallography measurements on 4.9 nm CsPbBr3 quantum dots with and without resonant 477 nm excitation at 3 ps delay, and reconstructs a 3D differential diffraction pattern from ~31,500 indexed crystals. The authors observe inward/outward shifts of the 200 and 110 Bragg peaks, respectively, which they interpret as a crystal-wide lattice deformation induced by a single exciton, i.e., an exciton polaron. Density functional theory on ~3 nm QDs gives a radial field with cations outward and anions inward, but fails to reproduce the 110 outward shift; a 'random hole localization' model with a surface-biased hole and species-dependent restoring forces is then tuned to reproduce the observed peak-shift pattern. The paper concludes that the exciton polaron in CsPbBr3 QDs is a mixed large/small polaron with a delocalized electron and a surface-biased localized hole.

Significance. If the experimental differential map is trustworthy and the single-exciton occupancy is correct, this would be the first direct structural observation of an exciton polaron in perovskite quantum dots in the single-exciton limit, and it would establish SFX on aerosolized QDs as a sensitive probe of ultrafast lattice deformations. The paper also provides a quantitative DFT-based starting point and a transparent, if simplified, electrostatic model of the deformation field. The methodological novelty is real: the 3D reciprocal-space merging of single-crystal snapshots from an aerosol stream, with multi-crystal indexing and per-crystal rescaling, is a useful advance. However, the central experimental evidence, the 3D difference map, is presented without any noise characterization, and the final model is tuned to the same data it claims to explain. These issues currently leave the principal claim under-supported.

major comments (4)
  1. [Fig. 3 and Methods, '3D intensity generation'] The 3D differential diffraction maps in Fig. 3a/b are the sole experimental evidence for the lattice deformation, yet they are shown without error bars, significance thresholds, or any null-hypothesis control. The Results section explicitly states that the integrated peak intensities, the virtual powder patterns, and the azimuthal average intensity show no statistically significant difference between pumped and dark data. Because the difference maps are built from two independently merged 3D volumes with different rescaling and rejection outcomes, systematic differences in crystal size, orientation coverage, background, or indexing quality could produce low-q-concentrated radial asymmetries like those in Fig. 3. The authors must demonstrate that the observed difference signal exceeds the noise floor of the same pipeline, e.g., by a split-half or permutation test on the dark/dark and pump/dark pairs, and report per-voxel uncertainties. Without this, the inference that resonant excitation distorts the lattice is not established.
  2. [Random hole localization model and SI S5] The random hole localization model is tuned to reproduce the 200 inward and 110 outward shifts. The main text states that by scanning the relative displacement amplitudes, the correct shifts require specific restoring-force parameters, and SI S5 shows that no restoring-force choice gives an outward 110 shift for a central hole; only a surface-biased hole position sampling (with a tunable bias) reproduces the data. Because these parameters are adjusted on the same dataset used for validation, the agreement in Fig. 5c is not an independent confirmation. The authors should provide a quantitative goodness-of-fit measure (e.g., chi-square over the relevant voxels), state the number of free parameters, and compare against the null model or a central-hole model with the same number of parameters, so the reader can judge whether the data actually constrain the surface-bias conclusion.
  3. [SI S2 and Results (occupation model)] The attributed single-exciton deformation relies on the occupation model in SI S2: a literature absorption cross-section, the kinetic model giving P0 = 0.368, P1 = 0.504, P2 = 0.128, and the untested assumption that two electron-hole pairs produce exactly double the distortion of one. The text says 'we expect to probe one electron-hole pair per QD in approximately 75% of the pumped frames', which ignores the 12.8% of QDs with two pairs. If the actual cross-section, pulse statistics, or biexciton contribution differ, the per-exciton deformation field would be mis-scaled. Please provide a sensitivity analysis of the inferred field under plausible variations of sigma_477, the biexciton absorption blocking, and the linear-scaling hypothesis, and discuss how these would affect the qualitative conclusions.
  4. [Discussion (first claim)] The Discussion states 'Our study provides the first structural evidence that resonant excitation in the single exciton limit leads to the formation of exciton-polarons in CsPbBr3 quantum dots.' This claim should be explicitly qualified by the statistical significance of the differential map and by the model-dependence of the interpretation. As written, the claim overreaches the evidence in the paper, especially given that the azimuthally averaged data show no significant difference.
minor comments (4)
  1. [Methods, Eq. (1)] The index set in Eq. (1) reads 'max_{i in {x,yz}}' and should presumably be 'max_{i in {x,y,z}}'.
  2. [Fig. 3b] The arrows in Fig. 3b point towards q = 0, but the text says the (200) peak shifts inward and the (110) outward. For the (200) peak, the arrow direction and the described shift are consistent only if 'inward' means toward the origin; please clarify in the caption for all four peaks.
  3. [Results, 'Optically induced lattice deformations'] The statement that 'no diffuse scattering is observed far from the BZ centre' is based on a visual inspection of the difference map; please report the noise level or a quantitative upper bound for the diffuse signal in those regions.
  4. [SI S4, Table S2] The reported slopes in Table S2 mix different units ('parts per million of the interatomic distance'); please specify the exact definition and the uncertainty propagation method used for the regression errors.

Circularity Check

1 steps flagged · score 6.0 of 10

The measured 3D differential diffraction is an independent experimental input, but the central charge-localization conclusion (surface-biased hole, weakly bound Br) is obtained by scanning free model parameters until the simulated peak shifts match those measured shifts, so that portion of the 'exciton-polaron' interpretation is a fitted result rather than an independent prediction.

  1. fitted input called prediction [Results, 'Random hole localization model' (final paragraph, around Fig. 5); SI S5 'Restoring force tuning']
    "By scanning the relative displacement field amplitudes (see Supplemental Information S3), we also observe that the correct peak shifts for the 200 peak requires that the Br atoms are more weakly restrained than the Cs and Pb atoms. This result indicates that upon photo-excitation, an exciton-polaron is formed that consists of a delocalized electron and a localized hole, the position of which is biased towards the outer parts of the QD."

    The 'correct peak shifts' are the measured 200-inward/110-outward Bragg-peak shifts, and the relative displacement amplitudes (spring constants k in SI Eq. S4) plus the hole-position bias are free parameters. The text states they were scanned until the model reproduced the measured shifts; the parameter set that achieves the match is then reported as the inferred physics (weakly restrained Br, surface-biased hole). The data are thus used both to set the model and to confirm it: SI S5 explicitly says a central hole can never give the 110 outward shift, which is why a surface-biased distribution was introduced. The agreement is by construction rather than an independent test.

full rationale

The core experimental result—a pump-induced 3D differential diffraction pattern with peak shifts—is not circular: it is a measurement, and the failure of the orthorhombic relaxation model and the partial mismatch of the DFT-only model are genuine comparisons. The single-exciton occupation model (SI S2) uses published absorption cross-sections and multiexciton kinetics, some from the authors' own prior work, but these are independent spectroscopic inputs, not this paper's deformation claim, so they do not make the derivation circular (they affect accuracy, not logic). The circular element is confined to the final random-hole-localization step: the surface-bias and per-species restoring-force constants are tuned until the simulated shifts match the measured shifts, and the tuned values are then presented as the physical conclusion about hole localization and Br mobility. That is a fit elevated to an inference, which is partial circularity. The absence of a split-half/permutation null test for the 3D difference maps is an important experimental robustness concern, but it is a correctness risk, not a circularity, and is not scored here.

Assumptions & free parameters 3 free parameters · 6 assumptions · 0 invented entities

The paper does not introduce a new particle, force, or conserved quantity. The polaron is an established quasi-particle, and the surface-biased hole distribution is an inferred model property rather than a newly postulated entity. The central claim rests on several domain assumptions about the DFT level of theory, singlet/triplet equivalence, biexciton doubling, and the spring model for displacements, together with fitted model parameters for restoring forces and surface bias.

free parameters (3)
  • Relative restoring force constants k_Cs, k_Pb, k_Br = Scanned in SI S5; a weak Br restoring force is required for the 200 inward shift
    In the random hole localization model, atomic displacements are set by k*d = q*E. The ratios of spring constants for Cs, Pb, and Br are tuned until the predicted peak shifts match the observed 200 and 110 behavior.
  • Surface-bias parameter in hole position sampling = Adjusted via the sampling formula in SI Eqs. 3 and 4; strong surface bias needed for the 110 outward shift
    The hole positions are drawn with a bias toward the QD surface. The authors state that introducing this surface bias reproduces the combination of inward 200 and outward 110 shifts.
  • Simulated QD size distribution and shape parameters = Gamma shape 2.0, mean size 5.4 nm, superellipsoid exponent 5.0
    Used in the intensity simulations to match observed truncation rods and peak widths. This affects the comparison of model and experiment, though it is less central to the peak-shift signs.
assumptions (6)
  • domain assumption The PBE density functional approximation adequately describes the excited-state geometry of CsPbBr3 quantum dots.
    All DFT geometry relaxations use the PBE functional with CP2K and effective core potentials, with no benchmark against higher-level methods in the paper.
  • domain assumption The singlet and triplet exciton geometries are effectively identical.
    The main text assumes that a spin flip of the exciton has no significant impact on atomic geometry, allowing the S=1 triplet state to represent the singlet exciton.
  • domain assumption Two electron-hole pairs produce exactly twice the lattice distortion of one pair.
    SI S2 uses this assumption to convert the computed biexciton probability into an effective number of probed pairs.
  • domain assumption Atomic displacements are proportional to the local electric field with a harmonic restoring force, k*d = q*E.
    This is the basis of the random hole localization model described in SI S5 and the Methods section.
  • domain assumption The delocalized electron can be modeled as a uniformly charged sphere with E(r) proportional to r/(s/2)^3.
    Methods Eq. 5 defines the electric field from the delocalized electron charge using a simple sphere model.
  • domain assumption Merging diffraction snapshots from many differently sized and oriented QDs yields a representative average 3D intensity map.
    The 3D reciprocal space reconstruction relies on orientational indexing of individual QDs and merging with per-crystal rescaling, implicitly assuming the ensemble average is meaningful for the differential signal.

how reviews work

0 comments
Cite this review

Pith. "Pith review of Direct observation of the exciton polaron by serial femtosecond crystallography on single CsPbBr$_3$ quantum dots." pith.science (2026). https://pith.science/paper/GEQP2HT2

@misc{pith2026250202343,
  author       = {Pith},
  title        = {Pith review of: Direct observation of the exciton polaron by serial femtosecond crystallography on single CsPbBr$_3$ quantum dots},
  year         = {2026},
  howpublished = {\url{https://pith.science/paper/GEQP2HT2}},
  note         = {Machine review of arXiv:2502.02343}
}
abstract

The outstanding opto-electronic properties of lead halide perovskites have been related to the formation of polarons. Nevertheless, the observation of the atomistic deformation brought about by one electron-hole pair in these materials has remained elusive. Here, we measure the diffraction patterns of single CsPbBr$_3$ quantum dots (QDs) with and without resonant excitation in the single exciton limit using serial femtosecond crystallography (SFX). By reconstructing the 3D differential diffraction pattern, we observe small shifts of the Bragg peaks indicative of a crystal-wide deformation field. Building on DFT calculations, we show that these shifts are consistent with the lattice distortion induced by a delocalized electron and a localized hole, forming a mixed large/small exciton polaron. This result creates a clear picture of the polaronic deformation in CsPbBr$_3$ QDs, highlights the exceptional sensitivity of SFX to lattice distortions in few-nanometer crystallites, and establishes an experimental platform for future studies of electron-lattice interactions.

Figures

Figures reproduced from arXiv: 2502.02343 by the authors.

Figure 1
Figure 1. b, a radial deformation is added to the NC, which is different in direction for the two sub-lattices. This de￾formation field changes the diffraction map, which leads to a differential diffraction for each Bragg peak as shown in Figure 1b. RESULTS Time-resolved aerosol serial femtosecond crystallography We synthesized a batch of CsPbBr3 NCs using pre￾viously published protocols based on size-selective pre￾cipitation… view at source ↗
Figure 2
Figure 2. a represents a typical diffraction snapshot con￾taining Bragg spots recorded as part of a sequence of 77182 frames (detailed statistics in Supplemental In￾formation S1). In this particular frame, we identified diffraction from three different QDs, as indicated by the coloured circles. Throughout the experiment, half the frames were collected 3 ps after resonant excitation of the QDs, which is long enough for any lat… view at source ↗
Figure 3
Figure 3. FIG. 3 [PITH_FULL_IMAGE:figures/full_fig_p004_3.png] view at source ↗
Figures from the paper (2 more)
Figure 4
Figure 4. Figure 4: FIG. 4 [PITH_FULL_IMAGE:figures/full_fig_p006_4.png]
Figure 5
Figure 5. Figure 5: FIG. 5 [PITH_FULL_IMAGE:figures/full_fig_p007_5.png]

Discussion (0). Continue with ORCID to comment.

Reference graph

Works this paper leans on

57 extracted references · 55 canonical work pages

  1. [1]

    Franchini, M

    C. Franchini, M. Reticcioli, M. Setvin, and U. Diebold, Polarons in materials, Nat. Rev. Mater. 6, 560 (2021)

    work page 2021

  2. [2]

    Shamsi, A

    J. Shamsi, A. S. Urban, M. Imran, L. De Trizio, and L. Manna, Metal halide perovskite nanocrystals: Synthe- sis, post-synthesis modifications, and their optical prop- erties, Chemical Reviews 119, 3296 (2019)

    work page 2019

  3. [3]

    G. E. Eperon, M. T. Horantner, and H. J. Snaith, Metal halide perovskite tandem and multiple-junction photo- voltaics, Nat. Rev. Chem. 1, 0095 (2017)

    work page 2017

  4. [4]

    Ghosh, E

    D. Ghosh, E. Welch, A. J. Neukirch, A. Zakhidov, and S. Tretiak, Polarons in halide perovskites: A perspective, J. Phys. Chem. Lett. 11, 3271 (2020), pMID: 32216360, https://doi.org/10.1021/acs.jpclett.0c00018

    work page doi:10.1021/acs.jpclett.0c00018 2020

  5. [5]

    Y. Lan, B. J. Dringoli, D. A. Valverde-Chavez, C. S. Ponseca, Jr., M. Sutton, Y. He, M. G. Kanatzidis, and D. G. Cooke, Ultrafast correlated charge and lattice mo- tion in a hybrid metal halide perovskite, Science Adv. 5, eaaw5558 (2019)

    work page 2019

  6. [6]

    X. Y. Zhu and V. Podzorov, Charge carriers in hybrid organic-inorganic lead halide perovskites might be pro- tected as large polarons, J. Phys. Chem. Lett. 6, 4758 (2015)

    work page 2015

  7. [7]

    D. W. deQuilettes, K. Frohna, D. Emin, T. Kirchartz, V. Bulovic, D. S. Ginger, and S. D. Stranks, Charge- carrier recombination in halide perovskites, Chem. Rev. 119, 11007 (2019)

    work page 2019

  8. [8]

    Gramlich, M

    M. Gramlich, M. W. Swift, C. Lampe, J. L. Lyons, M. D¨ oblinger, A. L. Efros, P. C. Sercel, and A. S. Urban, Dark and bright excitons in halide perovskite nanoplatelets, Adv. Sci. 9, 2103013 (2022)

    work page 2022

Show all 57 references
  1. [10]

    M. S. Kirschner, B. T. Diroll, P. Guo, S. M. Harvey, W. Helweh, N. C. Flanders, A. Brumberg, N. E. Watkins, A. A. Leonard, A. M. Evans, M. R. Wasielewski, W. R. Dichtel, X. Zhang, L. X. Chen, and R. D. Schaller, Pho- toinduced, reversible phase transitions in all-inorganic per...

    2019

  2. [11]

    S. A. Cuthriell, S. Panuganti, C. C. Laing, M. A. Quin- tero, B. Guzelturk, N. Yazdani, B. Traore, A. Brumberg, C. D. Malliakas, A. M. Lindenberg, V. Wood, C. Katan, J. Even, X. Zhang, M. G. Kanatzidis, and R. D. Schaller, Nonequilibrium lattice dynamics in photoexcited 2d per...

    2022 doi

  3. [12]

    Seiler, D

    H. Seiler, D. Zahn, V. C. A. Taylor, M. I. Bodnarchuk, Y. W. Windsor, M. V. Kovalenko, and R. Ernstorfer, Direct observation of ultrafast lattice distortions dur- ing exciton–polaron formation in lead halide perovskite nanocrystals, ACS Nano 17, 1979 (2023)

    2023

  4. [13]

    Yazdani, M

    N. Yazdani, M. I. Bodnarchuk, F. Bertolotti, N. Mas- ciocchi, I. Fureraj, B. Guzelturk, B. L. Cotts, M. Za- jac, G. Rain` o, M. Jansen,et al., Coupling to octahedral tilts in halide perovskite nanocrystals induces phonon- mediated attractive interactions between excitons, Na- ...

    2024

  5. [14]

    Trigo, M

    M. Trigo, M. Fuchs, J. Chen, M. Jiang, M. Cam- marata, S. Fahy, D. M. Fritz, K. Gaffney, S. Ghimire, A. Higginbotham, et al., Fourier-transform inelastic x-ray scattering from time-and momentum-dependent phonon– phonon correlations, Nature Physics 9, 790 (2013)

    2013

  6. [15]

    S. Wall, S. Yang, L. Vidas, M. Chollet, J. M. Glownia, M. Kozina, T. Katayama, T. Henighan, M. Jiang, T. A. Miller, et al. , Ultrafast disordering of vanadium dimers in photoexcited vo2, Science 362, 572 (2018)

    2018

  7. [16]

    Abbey, R

    B. Abbey, R. A. Dilanian, C. Darmanin, R. A. Ryan, C. T. Putkunz, A. V. Martin, D. Wood, V. Streltsov, M. W. Jones, N. Gaffney,et al., X-ray laser–induced elec- tron dynamics observed by femtosecond diffraction from nanocrystals of buckminsterfullerene, Science advances2, e160...

    2016

  8. [17]

    Mariette, M

    C. Mariette, M. Lorenc, H. Cailleau, E. Collet, L. Gu´ erin, A. Volte, E. Trzop, R. Bertoni, X. Dong, B. L´ epine,et al., Strain wave pathway to semiconductor-to-metal transi- tion revealed by time-resolved x-ray powder diffraction, Nature Communications 12, 1239 (2021)

    2021

  9. [18]

    Guzelturk, T

    B. Guzelturk, T. Winkler, T. W. J. Van de Goor, M. D. Smith, S. A. Bourelle, S. Feldmann, M. Trigo, S. W. Teitelbaum, H.-G. Steinr¨ uck, G. A. de la Pena, et al. , Visualization of dynamic polaronic strain fields in hybrid lead halide perovskites, Nature Materials 20, 618 (2021). 11

    2021

  10. [19]

    E. A. Schriber, D. W. Paley, R. Bolotovsky, D. J. Rosen- berg, R. G. Sierra, A. Aquila, D. Mendez, F. Poitevin, J. P. Blaschke, A. Bhowmick, et al. , Chemical crystal- lography by serial femtosecond x-ray diffraction, Nature 601, 360 (2022)

    2022

  11. [20]

    K. R. Beyerlein, C. Jooss, A. Barty, R. Bean, S. Boutet, S. S. Dhesi, R. B. Doak, M. F¨ orst, L. Galli, R. A. Kirian, et al., Trace phase detection and strain characterization from serial x-ray free-electron laser crystallography of a pr0.5ca0.5mno3 powder, Powder Diffraction ...

    2015

  12. [21]

    Aquila, M

    A. Aquila, M. S. Hunter, R. B. Doak, R. A. Kirian, P. Fromme, T. A. White, J. Andreasson, D. Arnlund, S. Bajt, T. R. M. Barends, et al., Time-resolved protein nanocrystallography using an x-ray free-electron laser, Opt. Express 20, 2706 (2012)

    2012

  13. [22]

    T. R. M. Barends, L. Foucar, A. Ardevol, K. Nass, A. Aquila, S. Botha, R. B. Doak, K. Falahati, E. Hart- mann, M. Hilpert, et al., Direct observation of ultrafast collective motions in co myoglobin upon ligand dissocia- tion, Science 350, 445 (2015)

    2015

  14. [23]

    Pande, C

    K. Pande, C. D. M. Hutchison, G. Groenhof, A. Aquila, J. S. Robinson, J. Tenboer, S. Basu, S. Boutet, D. P. DePonte, M. Liang, et al. , Femtosecond structural dy- namics drives the trans/cis isomerization in photoactive yellow protein, Science 352, 725 (2016)

    2016

  15. [24]

    H. N. Chapman, P. Fromme, A. Barty, T. A. White, R. A. Kirian, A. Aquila, M. S. Hunter, J. Schulz, D. P. DePonte, U. Weierstall,et al., Femtosecond x-ray protein nanocrystallography, Nature 470, 73 (2011)

    2011

  16. [25]

    M. A. Pfeifer, G. J. Williams, I. A. Vartanyants, R. Harder, and I. K. Robinson, Three-dimensional map- ping of a deformation field inside a nanocrystal, Nature 442, 63 (2006)

    2006

  17. [26]

    J. Maes, L. Balcaen, E. Drijvers, Q. Zhao, J. De Roo, A. Vantomme, F. Vanhaecke, P. Geiregat, and Z. Hens, Light absorption coefficient of cspbbr¡sub¿3¡/sub¿ per- ovskite nanocrystals, J. Phys. Chem. Lett. 9, 3093 (2018)

    2018

  18. [27]

    M. C. Brennan, J. Zinna, and M. Kuno, Existence of a size-dependent stokes shift in cspbbr3 perovskite nanocrystals, ACS Energy Letters 2, 1487 (2017)

    2017

  19. [28]

    Bielecki, M

    J. Bielecki, M. F. Hantke, B. J. Daurer, H. K. N. Reddy, D. Hasse, D. S. D. Larsson, L. H. Gunn, M. Svenda, A. Munke, J. A. Sellberg, L. Flueckiger, A. Pietrini, C. Nettelblad, I. Lundholm, G. Carlsson, et al. , Elec- trospray sample injection for single-particle imaging with ...

    2019 doi

  20. [29]

    S. Awel, R. A. Kirian, M. O. Wiedorn, K. R. Beyerlein, N. Roth, D. A. Horke, D. Oberth¨ ur, J. Knoska, V. Mar- iani, A. Morgan, et al. , Femtosecond X-ray diffraction from an aerosolized beam of protein nanocrystals, Jour- nal of Applied Crystallography 51, 133 (2018)

    2018

  21. [30]

    J. A. Rodriguez, M. I. Ivanova, M. R. Sawaya, D. Cas- cio, F. E. Reyes, D. Shi, S. Sangwan, E. L. Guenther, L. M. Johnson, M. Zhang, L. Jiang, M. A. Arbing, B. L. Nannenga, J. Hattne, J. Whitelegge, A. S. Brewster, M. Messerschmidt, S. Boutet, N. K. Sauter, T. Gonen, and D. S....

    2015

  22. [31]

    D. H. Wojtas, K. Ayyer, M. Liang, E. Mossou, F. Ro- moli, C. Seuring, K. R. Beyerlein, R. J. Bean, A. J. Morgan, D. Oberthuer, H. Fleckenstein, M. Heymann, C. Gati, O. Yefanov, M. Barthelmess, E. Ornithopoulou, L. Galli, P. L. Xavier, W. L. Ling, M. Frank, C. H. Yoon, T. A. Wh...

    2017

  23. [32]

    G. M. Sheldrick, Crystal structure refinement with shelxl, Acta Crystallographica Section C: Structural Chemistry 71, 3 (2015)

    2015

  24. [33]

    Cottingham and R

    P. Cottingham and R. L. Brutchey, On the crystal structure of colloidally prepared cspbbr3 quantum dots, Chem. Commun. 52, 5246 (2016)

    2016

  25. [34]

    Miyata, D

    K. Miyata, D. Meggiolaro, M. T. Trinh, P. P. Joshi, E. Mosconi, S. C. Jones, F. De Angelis, and X.-Y. Zhu, Large polarons in lead halide perovskites, Science ad- vances 3, e1701217 (2017)

    2017

  26. [35]

    Cannelli, N

    O. Cannelli, N. Colonna, M. Puppin, T. C. Rossi, D. Kin- schel, L. M. D. Leroy, J. L¨ offler, J. M. Budarz, A. M. March, G. Doumy, A. Al Haddad, M.-F. Tu, Y. Kumagai, D. Walko, G. Smolentsev, F. Krieg, S. C. Boehme, M. V. Kovalenko, M. Chergui, and G. F. Mancini, Quantify- ing...

    2021

  27. [36]

    Ayyer, P

    K. Ayyer, P. L. Xavier, J. Bielecki, Z. Shen, B. J. Daurer, A. K. Samanta, S. Awel, R. Bean, A. Barty, M. Berge- mann, et al. , 3d diffractive imaging of nanoparticle en- sembles using an x-ray laser, Optica 8, 15 (2021)

    2021

  28. [37]

    Zhuang, S

    Y. Zhuang, S. Awel, A. Barty, R. Bean, J. Bielecki, M. Bergemann, B. J. Daurer, T. Ekeberg, A. D. Estillore, H. Fangohr, et al., Unsupervised learning approaches to characterizing heterogeneous samples using x-ray single- particle imaging, IUCrJ 9, 204 (2022)

    2022

  29. [38]

    J. N. Clark, L. Beitra, G. Xiong, A. Higginbotham, D. M. Fritz, H. T. Lemke, D. Zhu, M. Chollet, G. J. Williams, M. Messerschmidt, B. Abbey, R. J. Harder, A. M. Kor- sunsky, J. S. Wark, and I. K. Robinson, Ultrafast three- dimensional imaging of lattice dynamics in individual ...

    2013

  30. [39]

    Mariani, A

    V. Mariani, A. Morgan, C. H. Yoon, T. J. Lane, T. A. White, C. O’Grady, M. Kuhn, S. Aplin, J. Koglin, A. Barty, and H. N. Chapman, OnDA: online data anal- ysis and feedback for serial X-ray imaging, Journal of Applied Crystallography 49, 1073 (2016)

    2016

  31. [40]

    Barty, R

    A. Barty, R. A. Kirian, F. R. Maia, M. Hantke, C. H. Yoon, T. A. White, and H. Chapman, Cheetah: software for high-throughput reduction and analysis of serial fem- tosecond x-ray diffraction data, Journal of applied crys- tallography 47, 1118 (2014)

    2014

  32. [41]

    C. Li, X. Li, R. Kirian, J. C. Spence, H. Liu, and N. A. Zatsepin, Spind: a reference-based auto-indexing algo- rithm for sparse serial crystallography data, IUCrJ 6, 72 (2019)

    2019

  33. [42]

    Allahgholi, J

    A. Allahgholi, J. Becker, A. Delfs, R. Dinapoli, P. G¨ ottlicher, H. Graafsma, D. Greiffenberg, H. Hirse- mann, S. Jack, A. Klyuev, H. Kr¨ uger, M. Kuhn, T. Lau- rus, A. Marras, D. Mezza, A. Mozzanica, J. Poehlsen, O. Shefer Shalev, I. Sheviakov, B. Schmitt, J. Schwandt, X. Sh...

    2019

  34. [43]

    J. P. Perdew, K. Burke, and M. Ernzerhof, Generalized gradient approximation made simple, Physical review let- ters 77, 3865 (1996)

    1996

  35. [44]

    T. D. K¨ uhne, M. Iannuzzi, M. Del Ben, V. V. Ry- bkin, P. Seewald, F. Stein, T. Laino, R. Z. Khaliullin, O. Sch¨ utt, F. Schiffmann, et al. , Cp2k: An electronic structure and molecular dynamics software package- quickstep: Efficient and accurate electronic structure cal- cul...

    2020

  36. [45]

    VandeVondele and J

    J. VandeVondele and J. Hutter, Gaussian basis sets for accurate calculations on molecular systems in gas and condensed phases, The Journal of chemical physics 127 (2007)

    2007

  37. [46]

    A. Jain, S. P. Ong, G. Hautier, W. Chen, W. D. Richards, S. Dacek, S. Cholia, D. Gunter, D. Skinner, G. Ceder, and K. a. Persson, Commentary: The Materials Project: A materials genome approach to accelerating materials innovation, APL Materials 1, 011002 (2013). Supplemental I...

    2013 arXiv

  38. [47]

    These geometries were obtained by imposing either a total spin S = 0, or a total spin S = 1

    General methodology To analyze the formation of a polaron in CsPbBr 3 QDs, we compared the relaxed QD geometry as obtained for the electronic ground state and the first excited state as predicted by density functional theory (DFT). These geometries were obtained by imposing ei...

  39. [48]

    All models were cut as cubes from a bulk CsPbBr3 crystal creating an inner framework of 5× 5× 5 Pb atoms, and an outer framework of 6× 6× 6 Cs atoms

    The CsPbBr3 quantum dot models The analysis made use of different charge neutral CsPbBr3 QD models with brute formula Cs200Pb125Br450. All models were cut as cubes from a bulk CsPbBr3 crystal creating an inner framework of 5× 5× 5 Pb atoms, and an outer framework of 6× 6× 6 Cs...

  40. [49]

    The diffraction pattern of the valence electrons The valence electron density was computed as a volumetric quantity on an equidistant 3D coordinate grid. To obtain the diffraction pattern with sufficient resolution in reciprocal space, the Fourier transform of the electron den...

  41. [50]

    By selecting q vectors using the same grid as for the valence electrons, a mutually compatible diffraction amplitude is obtained

    The diffraction pattern of the core electrons The contribution of the core electrons to the diffraction pattern was determined by consid- ering each core atom as a delta-point scatterer, such that the diffraction amplitude Fcore(k) could be determined by a direct summation of ...

  42. [51]

    Model nanocrystal relaxation

    The diffraction intensity difference For a given 2D planar slice in reciprocal space, the 2D diffraction difference pattern ∆Idiff is determined from Fval(q1,q 2) and Fcore(q1,q 2) according to: ∆Idiff (q1,q 2) =|FES,core(q1,q 2) +FES,val(q1,q 2)|2−|FGS,core(q1,q 2) +FGS,val(q...

  43. [52]

    Similar relaxation curves are obtained for all the model NCs analyzed

    Energy changes upon relaxation Figure S2a represents the evolution of the total energy of the tetra NC during the ge- ometry optimization of the ground state, starting from the hand-picked structure. Similar relaxation curves are obtained for all the model NCs analyzed. As sho...

  44. [53]

    Fig- ure S3a-c provides, as an example, the colour coded shifts along the x direction of the Cs, Pb and Br atoms

    Ground state / excited state atom displacement field As the core electrons will dominate the diffraction pattern, we first look at the changes in position of the core atoms when comparing the excited state and the ground state. Fig- ure S3a-c provides, as an example, the colou...

  45. [54]

    The pattern reflects the nearly cubic symmetry of the CsPbBr 3 QD lattice, featuring the most intense diffraction peaks for the (200), (220), and (400) directions

    Diffraction from the core electrons Figure S5a represents the diffraction pattern obtained for the relaxed ground state of the tetra NC. The pattern reflects the nearly cubic symmetry of the CsPbBr 3 QD lattice, featuring the most intense diffraction peaks for the (200), (220)...

  46. [55]

    Detailed analysis of the (200) diffraction To develop an understanding as to how the atomic shifts lead to a difference between the diffraction pattern of the excited state and the ground state, Figure S7 represents the simulated diffraction difference for the (200) peak, rela...

  47. [56]

    In the case of the box NC, for example, the vacancies are organized such that the x- axis is reduced to a C2 symmetry axis

    Comparing different CsPbBr 3 model QDs The symmetry of the model QD is affected by the arrangement of the Cs vacancies at the surface. In the case of the box NC, for example, the vacancies are organized such that the x- axis is reduced to a C2 symmetry axis. Opposite to the ca...

  48. [57]

    J. Maes, L. Balcaen, E. Drijvers, Q. Zhao, J. De Roo, A. Vantomme, F. Vanhaecke, P. Geiregat, and Z. Hens, J. Phys. Chem. Lett. 9, 3093 (2018)

    2018

  49. [58]

    Geiregat, O

    P. Geiregat, O. Erdem, M. Samoli, K. Chen, J. M. Hodgkiss, and Z. Hens, ACS Nano 18, 17794 (2024), pMID: 38913946, https://doi.org/10.1021/acsnano.4c03441. S18 FIG. S9. (3 top rows) Atom-selective diffraction intensity difference maps around the (200) peak and (bottom row) Tot...

    2024 doi

Pith tools

Reviewed August 9, 2026 · model on record in the stance chip above.