Hot electron and hole dynamics in thiol-capped CdSe quantum dots revealed by 2D electronic spectroscopy

Nils Lenngren, Mohamed A. Abdellah, Kaibo Zheng, Jaber Al Marri, Donatas Zigmantas, Karel Žídek, Tõnu Pullerits

Research output: Contribution to journalArticle

11 Citations (Scopus)

Abstract

Colloidal quantum dots (QDs) have attracted interest as materials for opto-electronic applications, wherein their efficient energy use requires the understanding of carrier relaxation. In QDs capped by bifunctional thiols, used to attach the QDs to a surface, the relaxation is complicated by carrier traps. Using 2D spectroscopy at 77 K, we follow excitations in thiol-capped CdSe QDs with state specificity and high time resolution. We unambiguously identify the lowest state as an optically allowed hole trap, and identify an electron trap with excited-state absorption. The presence of traps changes the initial dynamics entirely by offering a different relaxation channel. 2D electronic spectroscopy enables us to pinpoint correlations between states and to easily separate relaxation from different starting states. We observe the direct rapid trapping of 1S3/2, 2S3/2, and 1S1/2 holes, and several competing electron relaxation processes from the 1Pe state.

Original languageEnglish
Pages (from-to)26199-26204
Number of pages6
JournalPhysical Chemistry Chemical Physics
Volume18
Issue number37
DOIs
Publication statusPublished - 1 Jan 2016
Externally publishedYes

Fingerprint

Quantum Dots
Hot electrons
hot electrons
Sulfhydryl Compounds
thiols
Semiconductor quantum dots
Spectrum Analysis
quantum dots
Spectroscopy
Electrons
traps
electronics
spectroscopy
Hole traps
Electron traps
Relaxation processes
Excited states
excitation
electrons
trapping

ASJC Scopus subject areas

  • Physics and Astronomy(all)
  • Physical and Theoretical Chemistry

Cite this

Hot electron and hole dynamics in thiol-capped CdSe quantum dots revealed by 2D electronic spectroscopy. / Lenngren, Nils; Abdellah, Mohamed A.; Zheng, Kaibo; Al Marri, Jaber; Zigmantas, Donatas; Žídek, Karel; Pullerits, Tõnu.

In: Physical Chemistry Chemical Physics, Vol. 18, No. 37, 01.01.2016, p. 26199-26204.

Research output: Contribution to journalArticle

Lenngren, Nils ; Abdellah, Mohamed A. ; Zheng, Kaibo ; Al Marri, Jaber ; Zigmantas, Donatas ; Žídek, Karel ; Pullerits, Tõnu. / Hot electron and hole dynamics in thiol-capped CdSe quantum dots revealed by 2D electronic spectroscopy. In: Physical Chemistry Chemical Physics. 2016 ; Vol. 18, No. 37. pp. 26199-26204.
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