Vertical heterostructures of van der Waals materials enable new pathways to tune charge and energy transport characteristics in nanoscale systems. We propose that graphene Schottky junctions can host a special kind of photoresponse that is characterized by strongly coupled heat and charge flows that run vertically out of the graphene plane. This regime can be accessed when vertical energy trans...

Recent studies have predicted that heterostructure superlattices can enhance the effective thermoelectric power factor significantly through selective emission of hot carriers via thermionic emission. Here, we study the potential of SiGe/Si superlattices for power generation at high temperatures. A detailed theory based on Boltzmann transport equation is developed which takes into account multi...

Cold cathode electron emission technology is being developed in a variety of forms for spacecraft charge control applications, ranging from solar panel protection to deep space electric propulsion. Cold cathode emission can provide significant efficiency savings (power, weight, space, etc.) over classic approaches (such as thermionic emitters and plasma contactors) for many classes of missions....

Thermionic emission in heterostructures is investigated for integrated cooling of high power electronic and optoelectronic devices. This evaporative cooling is achieved by selective emission of hot electrons over a barrier layer from the cathode to the anode. As the energy distribution of emitted electrons is almost exclusively on one side of Fermi energy, upon the current flow, strong carrier-...

Surface functionalisation of diamond can produce negative electron affinity (NEA), where the conduction band lies higher in energy than vacuum level. Hydrogen termination is well-known to NEA on but be removed by temperatures above ∼700 °C, making it unsuitable for diamond-based thermionic applications, high are converted into electricity via an emission process. In this review article we give ...

We report measurements of the azimuthal emission nonuniformity of a gyrotron's thermionic cathode as determined from two experiments, one which determines the total emission and one which scans the emitted beam using a rotating probe. In the total emission experiment, which measured the total collector current over a range of voltages, the cathode's total work function spread was found to be 0....