Exciton dynamics of GaSe nanoparticle aggregates

H. Tu, K. Mogyorósi, D. F. Kelley

Research output: Contribution to journalArticle

18 Citations (Scopus)

Abstract

Time-resolved and static spectroscopic results on GaSe nanoparticle aggregates are presented to elucidate the exciton relaxation and diffusion dynamics. These results are obtained in room-temperature TOP/TOPO solutions at various concentrations. The aggregate absorption spectra are interpreted in terms of electrostatic coupling and covalent interactions between particles. The spectra at various concentrations may then be interpreted in terms of aggregate distributions calculated from a simple equilibrium model. These distributions are used to interpret concentration-dependent emission anisotropy kinetics and time-dependent emission spectral shifts. The emission spectra are reconstructed from the static emission spectra and decay kinetics obtained at a range of wavelengths. The results indicate that the aggregate z axis persistence length is about 9 particles. The results also show that the one-dimensional exciton diffusion coefficient is excitation wavelength dependent and has a value of about 2×10 -5 cm 2/s following 406 nm excitation. Although exciton diffusion results in very little energy relaxation, subsequent hopping of trapped electron/hole pairs occurs by a Forster mechanism and strongly red shifts the emission spectrum.

Original languageEnglish
Article number044709
JournalThe Journal of Chemical Physics
Volume122
Issue number4
DOIs
Publication statusPublished - 2005

Fingerprint

excitons
Nanoparticles
nanoparticles
emission spectra
Wavelength
spectral emission
Kinetics
Particle interactions
kinetics
wavelengths
red shift
excitation
Absorption spectra
Electrostatics
Anisotropy
diffusion coefficient
electrostatics
absorption spectra
anisotropy
LDS 751

ASJC Scopus subject areas

  • Atomic and Molecular Physics, and Optics

Cite this

Exciton dynamics of GaSe nanoparticle aggregates. / Tu, H.; Mogyorósi, K.; Kelley, D. F.

In: The Journal of Chemical Physics, Vol. 122, No. 4, 044709, 2005.

Research output: Contribution to journalArticle

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