Development of III-Nitride Based THz Inter-Subband Lasers

Abstract

The public reporting burden for this collection of information is estimated to average 1 hour per response, including the time for reviewing instructions, searching existing data sources, gathering and maintaining the data needed, and completing and reviewing the collection of information. III-Nitrides, due to their large conduction band offset and fast transition speeds, are promising constituents for intersubband (ISB) devices. In addition, III-Nitrides are characterized by a very large phonon energy (90 meV). This makes them ideally suited to the realization of near room temperature operating THz lasers. The objective of this program has been to demonstrate the potential for using III-Nitrides to realize a room temperature operating terahertz intersubband laser. In addition, III-Nitrides are characterized by a very large phonon energy (90 meV). This makes them ideally suited to the realization of near room temperature operating THz lasers. The objective of this program has been to demonstrate the potential for using III-Nitrides to realize a room temperature operating terahertz intersubband laser.As part of this contract, a comprehensive model of intersubband transitions was developed that takes into account the important effects of strain on bandstructure and piezo-as well as spontaneous-electric fields. Interband photoluminescence and intersubband absorption measurements were performed to help develop the modeling. We demonstrated the shortest MOCVD-grown III-Nitride intersubband absorption wavelength of 1.5 ?m as well as the longest intersubband wavelengths of 5.3 ?m, by any growth technique. In addition to investigating the optical properties we fabricated and tested both resonant tunneling diodes and quantum well infrared photodetectors in order to investigate quantum transport in III-Nitrides. Based on the refined III-Nitride intersubband models designs were also developed for room temperature terahertz emission via optical pumping. Electrical injection designs were also proposed for both polar and non-polar growth orientations. "Material and design engineering of (Al)GaN for high-performance avalanche photodiodes and intersubband applications," SPIE