Electron and hole dynamics in GaSe nanoparticles and GaSe-InSe nanoparticle heterojunctions

David F. Kelley, Haohua Tu, K. Mogyorósi, Xiang Bai Chen

Research output: Chapter in Book/Report/Conference proceedingConference contribution

Abstract

Femtosecond polarized transient absorption results are obtained for InSe and GaSe nanoparticles. The results indicate that the transient absorption spectrum of large GaSe particles is dominated by a size-independent, z-polarized hole intraband transition. The small particle spectra exhibit the same z-polarized hole transition and a much more intense x,y-polarized absorption that is assigned to a charge transfer transition from the conduction band to particle surface (edge) states. The intensity of this transition depends on the momentum state (Δ or M) of the electron, and Δ to M electron momentum relaxation results in a 15 ps absorption decay. These results are used to interpret analogous results obtained for mixed GaSe-InSe nanoparticle aggregates, also in the solution phase. The static absorption spectrum of the mixed aggregates exhibits a strong interparticle charge transfer absorption band at an energy slightly higher than the InSe bandgap. Photoexcitation of this band results in a polarized transient absorption spectrum and transient absorption kinetics characteristic of InSe valence band holes and GaSe conduction band electrons. This result indicates that with small GaSe particles, direct InSe to GaSe electron transfer occurs upon photoexcitation.

Original languageEnglish
Title of host publicationProceedings of SPIE - The International Society for Optical Engineering
Volume6325
DOIs
Publication statusPublished - 2006
EventPhysical Chemistry of Interfaces and Nanomaterials V - San Diego, CA, United States
Duration: Aug 15 2006Aug 17 2006

Other

OtherPhysical Chemistry of Interfaces and Nanomaterials V
CountryUnited States
CitySan Diego, CA
Period8/15/068/17/06

Fingerprint

Heterojunctions
heterojunctions
Absorption spectra
Nanoparticles
absorption spectra
nanoparticles
Electrons
Photoexcitation
Conduction bands
photoexcitation
Charge transfer
Momentum
conduction bands
electrons
charge transfer
momentum
Electron transitions
Valence bands
electron transfer
Energy gap

Keywords

  • Charge transfer
  • Nanoparticles
  • Optical spectroscopy

ASJC Scopus subject areas

  • Electrical and Electronic Engineering
  • Condensed Matter Physics

Cite this

Kelley, D. F., Tu, H., Mogyorósi, K., & Chen, X. B. (2006). Electron and hole dynamics in GaSe nanoparticles and GaSe-InSe nanoparticle heterojunctions. In Proceedings of SPIE - The International Society for Optical Engineering (Vol. 6325). [63250F] https://doi.org/10.1117/12.680083

Electron and hole dynamics in GaSe nanoparticles and GaSe-InSe nanoparticle heterojunctions. / Kelley, David F.; Tu, Haohua; Mogyorósi, K.; Chen, Xiang Bai.

Proceedings of SPIE - The International Society for Optical Engineering. Vol. 6325 2006. 63250F.

Research output: Chapter in Book/Report/Conference proceedingConference contribution

Kelley, DF, Tu, H, Mogyorósi, K & Chen, XB 2006, Electron and hole dynamics in GaSe nanoparticles and GaSe-InSe nanoparticle heterojunctions. in Proceedings of SPIE - The International Society for Optical Engineering. vol. 6325, 63250F, Physical Chemistry of Interfaces and Nanomaterials V, San Diego, CA, United States, 8/15/06. https://doi.org/10.1117/12.680083
Kelley DF, Tu H, Mogyorósi K, Chen XB. Electron and hole dynamics in GaSe nanoparticles and GaSe-InSe nanoparticle heterojunctions. In Proceedings of SPIE - The International Society for Optical Engineering. Vol. 6325. 2006. 63250F https://doi.org/10.1117/12.680083
Kelley, David F. ; Tu, Haohua ; Mogyorósi, K. ; Chen, Xiang Bai. / Electron and hole dynamics in GaSe nanoparticles and GaSe-InSe nanoparticle heterojunctions. Proceedings of SPIE - The International Society for Optical Engineering. Vol. 6325 2006.
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