Hot-Electron Nanobolometers Based on Disordered GaN Heterostructures

The proposed research is to develop hot electron THz nanobolometers (nanoHEB) with unprecedented low electron heat capacity (~10-19 J/K) for use in advanced heterodyne receivers, operating from liquid nitrogen to room temperatures. The sensor is based on the effect of electron heating in highly disordered two-dimensional electron gas (2DEG) in GaN heterostructures. Several methods for 2DEG nanoscale patterning, including the split-gate design, are proposed to fabricate the antenna coupled nanodevices. Because of the small electron heat capacity of the sensor, the proposed mixer requires the power of local oscillator (LO) at the level of 1-10¿W. With these sensors a single chain of THz multipliers may be used to provide LOs to entire array of sensors in imaging applications of heterodyne detectors. The picosecond hot electron cooling allows wide bandwidth (to 30 MHz). The project goals are to develop a technological route for fabrication of 2DEG AlInN/GaN microdevices, demonstrate effects of electron heating by 2?4 THz radiation in AlInN/GaN nanodevices, determine basic transport and kinetic parameters, and develop a preliminary prototype nanobolometer for 2 -4 THz range.