Infrared applications of III-nitride quantum dots

University Of New Mexico, Albuquerque NM

Investigators

Abstract

0225684 Manasreh Intersubband transitions in III-nitride multiple quantum dots will be investigated for their applications in the infrared spectral region. The polarization effect on the intersubband transitions measured at the normal incident, Brewster's angle, and waveguide configurations is an essential part of the current study. This will be important for optimizing the growth conditions and the sample design for normal incident coupling of photon-electron in advancing the sate of the art of infrared detectors. The normal incident coupling of photons with electrons that undergo the intersubband transition will eliminate the need for the extra steps of fabricating metal grating at the top of the device structure. Infrared devices based on intersubband transitions are extrinsic, i.e. the quantum structure has to be doped to populate the wells. Doping the quantum dots with silicon will be investigated using the local vibrational mode spectroscopy. One of the major parts of the PIs proposed research is directed toward solving various issues associated with the growth optimization and doping level. Since GaN-on-AlGaN interface possesses a large piezoelectric effect, the polarization-induced charges at the interfaces will be investigated. From the total integrated area of the intersubband transitions in the multiple quantum dots, he will accurately determine the carriers density, which is the sum of the carriers contributed from the intentionally Si-doped material and the polarization-induced charges formed at the GaN/AlGaN interfaces. The broader impact of the proposed research is to explore the infrared applications of III-nitride quantum structures and integrate the infrared detectors fabricated from these structures into pre-existing GaN ultraviolet sensors. The intersubband transitions in the multiple quantum dots will also be investigated for the 1.3-1.5 mm spectral range. This spectral range is technologically very important for long distance optical communication systems.