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Proceedings Paper

Enhancement of coherent acoustic phonons in InGaN multiple quantum wells
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Paper Abstract

Enhancement of coherent zone folded longitudinal acoustic phonon (ZFLAP) oscillations at terahertz frequencies was demonstrated in InGaN multiple quantum wells (MQWs) by using wavelength degenerate time resolved differential transmission spectroscopy. Screening of the piezoelectric field in InGaN MQWs by photogenerated carriers upon femtosecond pulse excitation gave rise to terahertz ZFLAPs, which were monitored at the Brillouin zone center in the transmission geometry. MQWs composed of 10 pairs InxGa1-xN wells and In0.03Ga0.97N barriers provided coherent phonon frequencies of 0.69-0.80 THz depending on the period of MQWs. Dependences of ZFLAP amplitude on excitation density and wavelength were also investigated. Possibility of achieving phonon cavity, incorporating a MQW placed between two AlN/GaN phonon mirrors designed to exhibit large acoustic gaps at the zone center, was also explored.

Paper Details

Date Published: 13 March 2015
PDF: 8 pages
Proc. SPIE 9363, Gallium Nitride Materials and Devices X, 93632J (13 March 2015); doi: 10.1117/12.2079245
Show Author Affiliations
Shopan D. Hafiz, Virginia Commonwealth Univ. (United States)
Fan Zhang, Virginia Commonwealth Univ. (United States)
Morteza Monavarian, Virginia Commonwealth Univ. (United States)
Vitaliy Avrutin, Virginia Commonwealth Univ. (United States)
Hadis Morkoç, Virginia Commonwealth Univ. (United States)
Ümit Özgür, Virginia Commonwealth Univ. (United States)


Published in SPIE Proceedings Vol. 9363:
Gallium Nitride Materials and Devices X
Jen-Inn Chyi; Hiroshi Fujioka; Hadis Morkoç, Editor(s)

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