Peter F. Satterthwaite

TL;DR: In this article, an ultraviolet (UV) photodetector employing the two-dimensional electron gas (2DEG) formed at the AlGaN/GaN interface as an interdigitated transducer (IDT) was characterized under optical stimulus.

TL;DR: In this article, the authors investigate the effects of changes in interfacial SiO2 resistance and capacitance in the oxide bilayer through both solid state leakage current and capacitive voltage measurements and through electrochemical methods applied to water splitting cells.

TL;DR: A significant reduction of bilayer resistance is reported, achieved by forming stable, ultrathin (<1.3 nm) SiO2 layers, allowing fabrication of water splitting photoanodes with hole conductances near the maximum achievable with the given catalyst and Si substrate.

Abstract: Extreme environments such as the Venus atmosphere are among the emerging applications that demand electronics that can withstand high-temperature oxidizing conditions. While wide-bandgap technologies for integrated electronics have been developed so far, they either suffer from gate oxide and threshold voltage ( $V_{th}$ ) degradation over temperature, large power supply requirements, or intrinsic base current. In this letter, AlGaN/GaN high electron mobility transistors (HEMTs) are suggested as an alternative platform for integrated sensors and analog circuits in extreme environments in oxidizing air atmosphere over a wide temperature range from 22°C to 400°C. An optimal biasing region, with a peak of transconductance ( $g_{m,peak}$ ) at −2.3 V with a negligible shift over the temperature range was observed. Moreover, remarkably low $V_{th}$ variation of 0.9% was observed, enabling the design of analog circuits that can operate over the entire temperature range. Finally, the operation of the devices at 400°C and 500°C over 25 hours was experimentally studied, demonstrating the stability of the DC characteristics after the 5 hours of burn-in, at 400°C.

TL;DR: In typical thermoelectric energy harvesters and sensors, the Seebeck effect is caused by diffusion of electrons or holes in a temperature gradient as mentioned in this paper, which can also have a phono...