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Abstract-We have developed a new methodology to investigate the dynamic ON-resistance (R ON ) of high-voltage GaN field-effect transistors. The new technique allows the study of R ON transients after a switching event over an arbitrary length of time. Using this technique, we have investigated dynamic R ON transients in AlGaN/GaN high-voltage, high electron-mobility transistors over a time span of ten decades under a variety of conditions. We find that right after an OFF-to-ON switching event, R ON can be several times higher under dc conditions. The increase in R ON is enhanced as the drain-source voltage in the OFF-state increases. The R ON recovery process after an OFF-to-ON switching event is characterized by a fast release of trapped charge through a temperature-independent tunneling process followed by conventional thermally activated detrapping on a longer timescale. After a high-power-to-ON switching event, in contrast, detrapping only takes place through a temperature-independent process. We postulate that the fast temperature-independent detrapping originates from interface states at the AlGaN barrier/AlN spacer interface. The thermally activated detrapping can arise from traps at the surface of the device or inside the AlGaN barrier. These findings are relevant in the quest to engineer a reliable GaN power switch with minimum dynamic R ON problems.

Humans vary in their ability to smell numerous odors [1-3], including those associated with food [4-6]. Odor sensitivity is heritable [7-11], with examples linking genetic variation for sensitivity to specific odors typically located near olfactory receptor (OR) genes [12-16]. However, with thousands of aromas and few deorphaned ORs [17, 18], there has been little progress toward linking variation at OR loci to odor sensitivity [19, 20]. We hypothesized that OR genes contain the variation that explains much of the differences in sensitivity for odors, paralleling the genetics of taste [21, 22], which affect the flavor experience of foods [23-25]. We employed a genome-wide association approach for ten food-related odors and identified genetic associations to sensitivity for 2-heptanone (p = 5.1 × 10(-8)), isobutyraldehyde (p = 6.4 × 10(-10)), β-damascenone (p = 1.6 × 10(-7)), and β-ionone (p = 1.4 × 10(-31)). Each locus is located in/near distinct clusters of OR genes. These findings increase the number of olfactory sensitivity loci to nine and demonstrate the importance of OR-associated variation in sensory acuity for food-related odors. Analysis of genotype frequencies across human populations implies that variation in sensitivity for these odors is widespread. Furthermore, each participant possessed one of many possible combinations of sensitivities for these odors, supporting the notion that everyone experiences their own unique "flavor world."