Time-resolved terahertz spectroscopy reveals the influence of charged sensitizing quantum dots on the electron dynamics in ZnO

Sesha Bamini N., Hynek Němec, Karel Žídek, Mohamed Abdellah, Jaber Al Marri, Pavel Chábera, Carlito Ponseca, Kaibo Zheng, Tönu Pullerits

Research output: Contribution to journalArticle

2 Citations (Scopus)

Abstract

Photoinitiated charge carrier dynamics in ZnO nanoparticles sensitized by CdSe quantum dots is studied using transient absorption spectroscopy and time-resolved terahertz spectroscopy. The evolution of the transient spectra shows that electron injection occurs in a two-step process, where the formation of a charge transfer state (occurring in several picoseconds) is followed by its dissociation within tens of picoseconds. The photoconductivity of electrons injected into the ZnO nanoparticles is lower than that of charges photogenerated directly in ZnO. We conclude that the motion of injected electrons in ZnO nanoparticles is strongly influenced by their interaction with positive charges left in the sensitizing quantum dots.

Original languageEnglish
Pages (from-to)6006-6012
Number of pages7
JournalPhysical Chemistry Chemical Physics
Volume19
Issue number8
DOIs
Publication statusPublished - 1 Jan 2017
Externally publishedYes

Fingerprint

Terahertz Spectroscopy
Terahertz spectroscopy
Quantum Dots
sensitizing
Nanoparticles
Semiconductor quantum dots
quantum dots
Electrons
nanoparticles
spectroscopy
Electron injection
electrons
Photoconductivity
Charge carriers
Absorption spectroscopy
photoconductivity
Charge transfer
charge carriers
Spectrum Analysis
absorption spectroscopy

ASJC Scopus subject areas

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

Cite this

Time-resolved terahertz spectroscopy reveals the influence of charged sensitizing quantum dots on the electron dynamics in ZnO. / N., Sesha Bamini; Němec, Hynek; Žídek, Karel; Abdellah, Mohamed; Al Marri, Jaber; Chábera, Pavel; Ponseca, Carlito; Zheng, Kaibo; Pullerits, Tönu.

In: Physical Chemistry Chemical Physics, Vol. 19, No. 8, 01.01.2017, p. 6006-6012.

Research output: Contribution to journalArticle

N., Sesha Bamini ; Němec, Hynek ; Žídek, Karel ; Abdellah, Mohamed ; Al Marri, Jaber ; Chábera, Pavel ; Ponseca, Carlito ; Zheng, Kaibo ; Pullerits, Tönu. / Time-resolved terahertz spectroscopy reveals the influence of charged sensitizing quantum dots on the electron dynamics in ZnO. In: Physical Chemistry Chemical Physics. 2017 ; Vol. 19, No. 8. pp. 6006-6012.
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