Thanks to the modern compound semiconductor growth and processing technologies, quantum wells and related semiconductor nanostructures have been widely investigated for infrared-terahertz devices. Here we propose a new general approach to make use of polar optical phonons in quantum wells for infrared (IR) and terahertz (THz) detection. Polar optical phonons strongly couple with both electrons and photons, and hence are potentially useful for photonic devices. As the first example, we show the coupling of phonon and intersubband transition leading to Fano resonance in photocurrent spectra. We investigate the phenomenon experimentally in specially designed GaAs/AlGaAs quantum well infrared photodetectors. Finally, we discuss the future research and potentials. Strongly coupled systems of electrons and phonons, i.e., polarons, may lead to new IR-THz photodetectors.

Date Published: 24 January 2011
PDF: 7 pages
Proc. SPIE 7945, Quantum Sensing and Nanophotonic Devices VIII, 79450X (24 January 2011); doi: 10.1117/12.874098

Published in SPIE Proceedings Vol. 7945:
Quantum Sensing and Nanophotonic Devices VIII
Manijeh Razeghi; Rengarajan Sudharsanan; Gail J. Brown, Editor(s)