Capturing the Crystalline Phase of Two-Dimensional Nanocrystal Superlattices in Action

Nano Lett. 2010 Mar 10;10(3):799-803. doi: 10.1021/nl9029048.


Critical photonic, electronic, and magnetic applications of two-dimensional nanocrystal superlattices often require nanostructures in perfect single-crystal phases with long-range order and limited defects. Here we discovered a crystalline phase with quasi-long-range positional order for two-dimensional nanocrystal superlattice domains self-assembled at the liquid-air interface during droplet evaporation, using in situ time-resolved X-ray scattering along with rigorous theories on two dimensional crystal structures. Surprisingly, it was observed that drying these superlattice domains preserved only an orientational order but not a long-range positional order, also supported by quantitative analysis of transmission electron microscopy images.

Publication types

  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Crystallization / methods*
  • Macromolecular Substances / chemistry
  • Materials Testing
  • Molecular Conformation
  • Nanostructures / chemistry*
  • Nanostructures / ultrastructure*
  • Nanotechnology / methods*
  • Particle Size
  • Phase Transition
  • Surface Properties


  • Macromolecular Substances