Journal Article

PUBDB-2021-03326

http://join2-wiki.gsi.de/foswiki/pub/Main/Artwork/join2_logo100x88.png Real-Time X-ray Scattering Discovers Rich Phase Behavior in PbS Nanocrystal Superlattices during In Situ Assembly

Lokteva, I. (Corresponding author)DESY* ; Dartsch, M.Extern*XFEL.EU* ; Dallari, F.XFEL.EU*DESY* ; Westermeier, F.XFEL.EU*DESY* ; Walther, M.XFEL.EU*DESY* ; Grübel, G.XFEL.EU*DESY* ; Lehmkühler, F.XFEL.EU*DESY*

2021
American Chemical Society Washington, DC

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Please use a persistent id in citations: doi:10.1021/acs.chemmater.1c02159  doi:10.3204/PUBDB-2021-03326

Abstract: During the self-organization of colloidal semiconductor nanoparticles by solvent evaporation, nanoparticle interactions are substantially determined by the organic ligands covering the inorganic core. However, the influence of the ligand grafting density on the assembly pathway is often not considered in experiments. Here, we carry out an in situ synchrotron small-angle X-ray scattering and X-ray cross-correlation analysis study of the real-time assembly of oleic acid-capped PbS nanocrystals at a low ligand coverage of 2.7 molecules/nm2. With high temporal and spatial resolution, we monitor the transitions from the colloidal suspension through the solvated superlattice states into the final dried superstructure. In a single in situ experiment, we observe a two-dimensional hexagonal, hexagonal close-packed, body-centered cubic, body-centered tetragonal (with different degrees of tetragonal distortion), and face-centered cubic superlattice phases. Our results are compared to the self-organization of PbS nanocrystals with a higher ligand coverage up to 4.5 molecules/nm2, revealing different assembly pathways. This highlights the importance of determining the ligand coverage in assembly experiments to approach a complete understanding of the assembly mechanism as well as to be able to predict and produce the targeted superstructures.

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Contributing Institute(s):

1. Coherent X-ray Scattering (FS-CXS)
2. PETRA-S (FS-PETRA-S)
3. FS-Photon Science (FS-PS)

Research Program(s):

1. 632 - Materials – Quantum, Complex and Functional Materials (POF4-632) (POF4-632)
2. 6G3 - PETRA III (DESY) (POF4-6G3) (POF4-6G3)
3. DFG project 390715994 - EXC 2056: CUI: Advanced Imaging of Matter (390715994) (390715994)
4. DFG project 194651731 - EXC 1074: Hamburger Zentrum für ultraschnelle Beobachtung (CUI): Struktur, Dynamik und Kontrolle von Materie auf atomarer Skala (194651731) (194651731)

Experiment(s):

1. PETRA Beamline P10 (PETRA III)

Appears in the scientific report 2021

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Database coverage:
; ; Clarivate Analytics Master Journal List ; Current Contents - Engineering, Computing and Technology ; Current Contents - Physical, Chemical and Earth Sciences ; Ebsco Academic Search ; Essential Science Indicators ; IF >= 5 ; JCR ; Nationallizenz ; SCOPUS ; Science Citation Index Expanded ; Web of Science Core Collection

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