Large Band Edge Tunability in Colloidal Nanoplatelets

Qunfei Zhou, Yeongsu Cho, Shenyuan Yang, Emily A. Weiss, Timothy C. Berkelbach, Pierre Darancet

Research output: Contribution to journalArticle

Abstract

We study the impact of organic surface ligands on the electronic structure and electronic band edge energies of quasi-two-dimensional (2D) colloidal cadmium selenide nanoplatelets (NPLs) using density functional theory. We show how control of the ligand and ligand-NPL interface dipoles results in large band edge energy shifts, over a range of 5 eV for common organic ligands with a minor effect on the NPL band gaps. Using a model self-energy to account for the dielectric contrast and an effective mass model of the excitons, we show that the band edge tunability of NPLs together with the strong dependence of the optical band gap on NPL thickness can lead to favorable photochemical and optoelectronic properties.

Original languageEnglish
Pages (from-to)7124-7129
Number of pages6
JournalNano letters
Volume19
Issue number10
DOIs
Publication statusPublished - Oct 9 2019

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Keywords

  • Colloidal nanoplatelet
  • DFT
  • band edge energies
  • band gap
  • effective mass model
  • self-energy correction

ASJC Scopus subject areas

  • Bioengineering
  • Chemistry(all)
  • Materials Science(all)
  • Condensed Matter Physics
  • Mechanical Engineering

Cite this

Zhou, Q., Cho, Y., Yang, S., Weiss, E. A., Berkelbach, T. C., & Darancet, P. (2019). Large Band Edge Tunability in Colloidal Nanoplatelets. Nano letters, 19(10), 7124-7129. https://doi.org/10.1021/acs.nanolett.9b02645