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Experimental results on electron transport and microwave noise are used to investigate, in the electron temperature approximation, dissipation of hot-electron energy in a biased donor-doped 4H-SiC channel (n=2·1017 cm-3). The electron energy relaxation time is estimated to be 2.8±1 ps in the electric-field range below 25 kV/cm at room temperature. Longitudinal-optical phonons are found responsible for electron energy dissipation when the supplied power ranges from 0.5 to 25 nW per electron. In this range, accumulation of nonequilibrium (hot) longitudinal-optical phonons takes place. Equivalent hot-phonon temperature reaches 3000 K near 30 kV/cm, hot-phonon lifetime is comparable to the electron energy relaxation time. Dependence of the lifetime on electric field is weak in the investigated range of electric fields below 50 kV/cm. [ABSTRACT FROM AUTHOR]

Presents a study which reviewed the principal substrate and epitaxial issues for the development of high power silicon carbide devices. Cross section of the system design used for the seeded sublimation technique for bulk growth of silicon carbide; Increase in water diameter as a function of time; Details of large area alternative substrates.

Describes second harmonic generation in cubic silicon carbide at a wavelength of 1.06 micrometer. Characterization of the epitaxial layers; Value of the effective second order nonlinear susceptibility; Effect of absorption.

Abstract: Epitaxial graphene grown on SiC substrates is one of the most promising methods for achieving large-area uniform graphene films. Our experimental results demonstrate that graphene layers grown on both the Si and the C-faces of semi-insulating 6H-SiC can offer very high NO2 detection sensitivity and selectivity, as well as fast response time. Exposure to only 500ppb NO2 reduced the conductivity by 2.25%, while 18ppm caused a reduction of 10%. In contrast, high concentrations of commonly interfering gases, namely, CO2 (20%), H2O (saturated vapor), NH3 (550ppm), and pure O2 increased the conductivity by a maximum of 2%. Graphene on the C-face of SiC resulted in somewhat lower sensitivity for the test gases, with the conductivity changing in an opposite direction compared to the Si-face for any particular gas. The conductance changes due to molecular adsorption were correlated with changes in the surface work function (SWF). Measurements conducted at higher temperature showed significantly higher changes in conductivity and shorter response times. [Copyright &y& Elsevier]