Enhanced Valley Splitting of Exciton Emission in Colloidal PbSe Quantum Dots When the Interdot Distance Coincides with Onset of Förster Resonance Energy Transfer

Takahisa Omata, Hiroshi Asano, Masahiro Sakai, Yoshikazu Terai, Masao Kita

Research output: Contribution to journalArticlepeer-review

Abstract

Photoluminescence (PL) emission of colloidal PbSe/CdSe core/shell quantum dots (QDs, CdSe shell thickness: 0.2 nm) at the lowest exciton state was investigated at room temperature and varying inter-QD distance (L = 7-240 nm) by changing the QD concentration. A distinct enhancement of the valley splitting of PbSe QDs was observed upon reducing L. Simultaneously, there was a redshift in the emission due to Förster resonance energy transfer (FRET), when the L value was still sufficiently large (7 nm ≤ L ≤ 50 nm) so that the wave functions of different QDs do not overlap. The enhanced valley splitting under no apparent external field is quite interesting as a method to control the valley splitting. The electronic coupling leading to FRET may enhance the valley splitting, because it occurs in an identical range of L.

Original languageEnglish
Pages (from-to)3120-3126
Number of pages7
JournalThe journal of physical chemistry letters
Volume12
Issue number12
DOIs
Publication statusPublished - 2021 Apr 1

ASJC Scopus subject areas

  • Materials Science(all)
  • Physical and Theoretical Chemistry

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