2D Crystals in Three Dimensions: Electronic Decoupling of Single-Layered Platelets in Colloidal Nanoparticles

Research output: Contribution to journalResearch articleContributedpeer-review

Contributors

  • Roman Kempt - , Leipzig University (Author)
  • Agnieszka Kuc - , Leipzig University, Helmholtz-Zentrum Dresden-Rossendorf (Author)
  • Jae Hyo Han - , Institute for Basic Science, Yonsei University (Author)
  • Jinwoo Cheon - , Institute for Basic Science, Yonsei University (Author)
  • Thomas Heine - , Chair of Theoretical Chemistry, Leipzig University, Helmholtz-Zentrum Dresden-Rossendorf (Author)

Abstract

2D crystals, single sheets of layered materials, often show distinct properties desired for optoelectronic applications, such as larger and direct band gaps, valley- and spin-orbit effects. Being atomically thin, the low amount of material is a bottleneck in photophysical and photochemical applications. Here, the formation of stacks of 2D crystals intercalated with small surfactant molecules is proposed. It is shown, using first principles calculations, that the very short surfactant methyl amine electronically decouples the layers. The indirect–direct band gap transition characteristic for Group 6 transition metal dichalcogenides is demonstrated experimentally by observing the emergence of a strong photoluminescence signal for ethoxide-intercalated WSe2 and MoSe2 multilayered nanoparticles with lateral size of about 10 nm and beyond. The proposed hybrid materials offer the highest possible density of the 2D crystals with electronic properties typical of monolayers. Variation of the surfactant's chemical potential allows fine-tuning of electronic properties and potentially elimination of trap states caused by defects.

Details

Original languageEnglish
Article number1803910
JournalSmall
Volume14
Issue number51
Publication statusPublished - 20 Dec 2018
Peer-reviewedYes

External IDs

PubMed 30398000

Keywords

Keywords

  • 2D materials, heterostructures, intercalates, optoelectronics, photoluminescence