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This work provides the first demonstration of a multipoint fit from theory to experiment for step-etched junction terminations on vertical gallium nitride (GaN) devices. Viable edge termination methods in GaN are limited due to challenges with selective-area doping. We report on a study that determines the optimal charge in the junction termination extension (JTE) of a GaN-based p-n diode to aid in the design of multizone JTEs. Experimental results show a step-thickness offset compared to theoretical prediction, which is attributed to plasma-induced etch damage, as well as variation in passivation-related charge, surface charge, and doping profile variations. Results are supported by electroluminescence imaging, which confirms the match from theory to experiment.

This article provides an overview of power semiconductor devices (PSDs) for the distributed energy resource (DER) system. To begin with, an overview of electrically triggered silicon carbide (SiC) and gallium nitride (GaN) devices followed by a brief narration of ultrawide bandgap (UWBG) PSDs and, subsequently, an overview of optically activated PSDs encompassing photoconductive semiconductor switch (PCSS) and optical bipolar PSDs are provided. Finally, an overview of PSD packaging and reliability is captured.

•Lines 7-8: Furthermore, state-of-the-art vertical GaN devices including fin-JFETs, CAVETs, and MOSFETs have been reported with blocking voltages up to 1.6 kV [ 4, 5, 6].•Lines 99-101: Consequently, no leakage ramp-up or avalanche behavior was observed. On average, devices only reached 30% of the theoretical blocking voltage before failing. Several factors can reduce the robustness of the gate dielectric such as material defects, non-uniform thickness, and interface roughness. Further associated challenges will be discussed Section 4.•Lines 148-149: It should be noted that initial reports on regrown devices such as fin JFETs are emerging [ 4 ], however, the leakage currents are excessively high compared to traditional commercial offerings.

Two platinum(II)-catalyzed heterocyclization-migration reactions that provide five-membered heterocycle products are described. With 5 mol-% of PtCl2 as a catalyst, 2-alkynyl-2-hydroxy carbonyl compounds 1 are converted into 3(2H)-furanones 2 at 80 °C in moderate to excellent yields under very mild reaction conditions. The reaction is proposed to proceed through an oxonium ion intermediate B, which triggers a stereospecific 1,2-shift analogous to an α-ketol rearrangement. When exploited in a different manner, the 2-alkynyl-2-hydroxy carbonyl compounds 1 afford 3-pyrrolones 3 in 33–81 % yield. For this purpose, the starting compounds 1 are treated with primary amines in the presence of 5 mol-% of PtCl2 at 100 °C in a convenient one-pot process. These cyclization-migration reactions give novel access to 3(2H)-furanones and 3-pyrrolones in which the 2-position bears aryl or alkyl substituents. Synthetically challenging spirocyclic compounds can be prepared in this fashion by ring contraction. Studies that define the scope and limitations of the cyclization-migration synthesis of heterocyclic systems are also described. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007)

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ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.