We report here the observation of piezoelectricity-induced terahertz photon absorption related to confined acoustic phonons in nanoparticles. Terahertz photon inactive (l=0) breathing modes become terahertz photon active in wurtzite CdSe nanocrystals due to the piezoelectric coupling. Obvious absorption peaks related to (l=0) modes appeared in the terahertz absorption spectra and the frequency of the peaks were inversely proportional to the size of the CdSe nanocrystals. This piezoelectrically coupled electric vibration provides a mechanism for low-dimensional systems to convert a terahertz photon into a phonon of the same frequency.
|Journal||Physical Review B - Condensed Matter and Materials Physics|
|Publication status||Published - 2008 Feb 26|
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Condensed Matter Physics