11:15 AM–1:15 PM, Wednesday, March 23, 2005
LACC - 405
Sponsoring Unit:
FIAP
Chair: Fran Wise, Cornell University
Abstract ID: BAPS.2005.MAR.P15.5
12:27 PM–12:39 PM
Khan A. Alim
Vladimir A. Fonoberov
Alexander A. Balandin
(Nano-Device Laboratory (http://ndl.ee.ucr.edu/), Department of Electrical Engineering, University of California, Riverside, CA 92521)
Nanostructures made of ZnO have recently attracted attention due to their proposed applications in low-voltage and short-wavelength electro-optical devices. However, the origin of the observed phonon frequency shifts in such nanostructures is not always understood. We carried out both resonant and non-resonant Raman measurements for 20 nm-diameter ZnO quantum dots (QDs) and bulk ZnO reference samples [1]. A comparison with a recently developed theory [2], allowed us to clarify the origin of the phonon frequency shifts in ZnO QDs. It was found that the phonon confinement results in phonon frequency shifts of only few cm$^{-1}$. At the same time, the UV laser heating of the QD ensemble was found to induce a large red shift of phonon frequencies for up to 14 cm$^{-1}$. The authors acknowledge the support of MARCO and its Functional Engineered Nano Architectonics (FENA) Focus Center. [1] K.A. Alim, V.A. Fonoberov, and A.A. Balandin, Appl. Phys. Lett., in review (2004). [2] V.A. Fonoberov and A.A. Balandin, Phys. Stat. Solidi C \textbf{1}, 2650 (2004); cond-mat/0405681; cond-mat/0411742.
To cite this abstract, use the following reference: http://meetings.aps.org/link/BAPS.2005.MAR.P15.5