Cooling-Induced Order-Disorder Phase Transition in CsPbBr3 Nanocrystal Superlattices

Umberto Filippi, Stefano Toso, Matteo L. Zaffalon, Andrea Pianetti, Zhanzhao Li, Sergio Marras, Luca Goldoni, Francesco Meinardi, Sergio Brovelli, Dmitry Baranov, Liberato Manna

Forskningsoutput: TidskriftsbidragArtikel i vetenskaplig tidskriftPeer review

Sammanfattning

Perovskite nanocrystal superlattices are being actively studied after reports have emerged on collective excitonic properties at cryogenic temperatures, where energetic disorder is minimized due to the frozen lattice vibrations. However, an important issue related to structural disorder of superlattices at low temperatures has received little attention to date. In this work, it is shown that CsPbBr3 nanocrystal superlattices undergo a reversible order–disorder transition upon cooling to 90 K. The transition consists of the loss of structural coherence, that is, increased nanocrystal misalignment, and contraction of the superlattices, as revealed by temperature-dependent X-ray diffraction, and is ascribed to the solidification of ligands (on the basis of Raman spectroscopy). Introducing shorter amines on the nanocrystal surface allows to mitigate these changes, improve order, and shorten interparticle distance. It is demonstrated that the low temperature phase of the short ligand-capped nanocrystal superlattices is characterized by a strong exciton migration observable in the photoluminescence decay, which is due to the shrinkage of the inter-nanocrystal distance.
Originalspråkengelska
Artikelnummere2410949
TidskriftAdvanced Materials
DOI
StatusE-pub ahead of print - 2024 nov. 20

Bibliografisk information

© 2024 The Author(s). Advanced Materials published by Wiley‐VCH GmbH.

Ämnesklassifikation (UKÄ)

  • Nanoteknik
  • Materialkemi
  • Den kondenserade materiens fysik

Citera det här