ABSTRACT
The growth of AlGaN/GaN MQWs is investigated with the objective of achieving intersubband transition (ISBT) at a wavelength in the near infrared region. The quality of MQWs was affected by the barrier thickness. By adopting thin barriers, we have succeeded in growing high-quality Al0.65Ga0.35N/GaN MQWs (30 wells) in spite of a large lattice mismatch. Strong photoluminescence signals from the quantum level have been detected. By the ATR (attenuated total reflectance) method, intersubband absorptions have been observed at a wavelength of 2.9-3.1 μm. This result is promising in regard to the future application of ISBT to high-speed optical switches.
