Self-Organized Quantum Dots for High-Performance Multi-Spectral Infrared Photodetectors

This AFRL Nanotechnology Initiative program focused on uncovering and overcoming the fundamental limiting factors in realizing high performance self-assembled quantum dot SAQD based infrared photodetectors QDIPs in the mid-infrared MIR,3 5 m andor long wavelength infrared LWIR, 8 12 m regime. This Final Technical Report summarizes the major accomplishments made in this program. The highlights include 1 successful growth of extended defect-free multiple quantum dot MQD structures maintaining high intra- and layer-to-layer uniformity of the SAQDs, 2 analysis of electron occupancy in SAQDs and the potential profile in QDIP structures to guide doping optimization, 3 identification, characterization, and reduction of deep level traps existing in the MBE molecular beam epitaxygrown GaAs spacer layers by a factor of 20 and their impact on QDIP electrical characteristics, and 4 the design and implementation of resonant cavity-enhanced QDIP structures for QDIP performance enhancement by a factor of over ten.