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13 March 2015 Enhancement of coherent acoustic phonons in InGaN multiple quantum wells
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Proceedings Volume 9363, Gallium Nitride Materials and Devices X; 93632J (2015)
Event: SPIE OPTO, 2015, San Francisco, California, United States
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.
© (2015) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
Shopan D. Hafiz, Fan Zhang, Morteza Monavarian, Vitaliy Avrutin, Hadis Morkoç, and Ümit Özgür "Enhancement of coherent acoustic phonons in InGaN multiple quantum wells", Proc. SPIE 9363, Gallium Nitride Materials and Devices X, 93632J (13 March 2015);


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