Research
Thermoradiative Power
We invented a method to harvest energy from an ambient temperature source that passes its heat through a conversion device and is radiated out into outer space, which is cold. So that the atmosphere does not interfere with the radiation, it is limited to a narrow band of wavelengths over which the atmosphere is highly transparent. Continuous electrical power is generated during nighttime, as well as during the day.
Casimir Power
We have developed devices which produce power that appears to result from zero-point energy quantum fluctuations. The formation of a Casimir cavity on one side of a metal–insulator–metal (MIM) tunneling device induces a measurable electrical current between the two metal layers with no applied voltage.
Geometric Diode
We invented and demonstrated geometric diodes, which are planar conductors patterned asymmetrically to provide electrical asymmetry. They have exhibited high-frequency rectification in infrared rectennas.
Resonant Tunneling
Using quantum-well engineering, we demonstrated the effects of resonant tunneling in metal-double-insulator-metal (MI2M) diodes, an effect that our lab predicted two decades ago but was not demonstrated at the low voltages needed for energy harvesting rectenna applications.
Nonstoichiometric Al2O3 for Optical Rectennas
Using a nonstoichiometric Al2O3 layer, which forms a smaller barrier with the adjacent metal than that for stoichiometric Al2O3, we demonstrated rectennas with improved total conversion efficiencies and detectivities beyond the best achieved previously for a structure that does not take advantage of resonant tunneling.
Traveling-Wave Diode for Optical Rectennas
We demonstrated that the transmission line impedance of traveling-wave diodes can circumvent resistance-capacitance time-constant limitations of metal-insulator-metal diodes in rectennas operating at optical frequencies.