We present results of an experimental and theoretical study of the temperature dependence of the off-state breakdown voltage of InAlAsDnGaAs high electron mobility transistors (HEMTs). We find that the breakdown voltage (BV) has a negative temperature coefficient that is more prominent for lower values of the extrinsic sheet carrier concentration (nJ. Structural parameters such as the insulator...

We have fabricated and measured low barrier (30-150 meV) Schottky diodes using n+InGaAs/nGaAs pseudomorphic structures with up to 1.5% lattice mismatch. The I-V measurements at temperatures from 4 to 200 K show rectifying behavior and indicate transport mechanisms which range from tunneling to thermionic emission. The transport properties and barrier height determinations indicate that the band...

IN the course of an investigation into the value of the glass electrode as a means of making continuous records of the hydrogen ion concentration of circulating blood, it was found, in the preliminary experiments in which estimations were made on single samples, that there were several sources of serious error. The difficulties encountered in devising a satisfactory apparatus for measuring glas...

The fabrication and characterization of single element p-type SiGe/Si superlattice coolers are described. Superlattice structures were used to enhance the device performance by reducing the thermal conductivity between the hot and the cold junctions, and by providing selective emission of hot carriers through thermionic emission. The structure of the samples consisted of a 3 μm thick symmetrica...

We have investigated the temperature dependence of photoluminescence ~PL! properties of a number of self-organized InAs/GaAs heterostructures with InAs layer thickness ranging from 0.5 to 3 ML. The temperature dependence of InAs exciton emission and linewidth was found to display a significant difference when the InAs layer thickness is smaller or larger than the critical thickness around 1.7 M...

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....

SiGe is one of the best thermoelectric materials for high temperature applications. Superlattice structures can further enhance the thermoelectric properties by reducing the thermal conductivity and by increasing the Seebeck coefficient via selective emission of hot electrons through thermionic emission. SiGe/Si superlattice structures were grown on a silicon wafer using molecular beam epitaxy....

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-...