AlInGaN-Based Superlattice Terahertz Source

WaveBand Corporation in collaboration with Virginia Commonwealth University proposes to design and fabricate a new sub-millimeter source based on an InAlGaN superlattice (SL). Semiconductor SLs have proven their ability to deliver high-frequency current oscillations caused by specific electron dynamics in a narrow miniband. For this project, WaveBand proposes to demonstrate SLs based on one of the GaN-family materials that deliver high temperature and high power operation superior to those provided by conventional III-V materials based on GaAs and InAs alloys. The idea of Bloch oscillators has been around for a while, yet actual example has not been demonstrated. The reason is that dc-current instability prevents oscillations at high frequency. The innovation of the proposed work is that we plan to use short-period SLs with complex miniband electron energy dispersion that suppresses the dc-instability and allows electrons to oscillate at multiples of the fundamental Bloch frequency. MBE-growth of short-period SLs will be performed using formation of spontaneous superlattices from an immiscible composition.