83 research outputs found
Monte Carlo Simulations of Electron Transport Characteristics of Ternary Carbide Al4SiC4
Electron transport characteristics of a novel wide band gap ternary carbide, Al4SiC4, to be used for efficient power and optoelectronic applications, are predicted using ensemble Monte Carlo (MC) simulations. The MC simulations use a mixture of material parameters obtained from density functional theory (DFT) calculations and experiment, with a preference for the experimental data if they are known. The DFT calculations predict a band gap of 2.48 eV, while the experimental measurements give a band gap between 2.78 and 2.8 eV. We have found that the electron effective mass in the two lowest valleys (M and K) is highly anisotropic; in the K valley, mt* = 0.5678 me and ml* = 0.6952 me, and for the M valley, mt* = 0.9360 me and ml* = 1.0569 me. We simulate electron drift velocity and electron mobility as a function of applied electric field as well as electron mobility as a function of doping concentration in Al4SiC4. We predict a peak electron drift velocity of 1.35 × 107 cm s–1 at an electric field of 1400 kV cm–1 and a maximum electron mobility of 82.9 cm2 V–1 s–1. We have seen diffusion constants of 2.14 cm2 s–1 at a low electric field and 0.25 cm2 s–1 at a high electric field. Finally, we show that Al4SiC4 has a critical field of 1831 kV cm–1
Large area quasi-free standing monolayer graphene on 3C-SiC(111)
Large scale, homogeneous quasi-free standing monolayer graphene is obtained
on cubic silicon carbide, i.e. the 3C-SiC(111) surface, which represents an
appealing and cost effective platform for graphene growth. The quasi-free
monolayer is produced by intercalation of hydrogen under the interfacial,
(6root3x6root3)R30-reconstructed carbon layer. After intercalation, angle
resolved photoemission spectroscopy (ARPES) reveals sharp linear pi-bands. The
decoupling of graphene from the substrate is identified by X-ray photoemission
spectroscopy (XPS) and low energy electron diffraction (LEED). Atomic force
microscopy (AFM) and low energy electron microscopy (LEEM) demonstrate that
homogeneous monolayer domains extend over areas of hundreds of
square-micrometers.Comment: 4 pages, 3 figures, Copyright (2011) American Institute of Physics.
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Al4SiC4 w\"urtzite crystal: structural, optoelectronic, elastic and piezoelectric properties
New experimental results supported by theoretical analyses are proposed for
aluminum silicon carbide (Al4SiC4). A state of the art implementation of the
Density Functional Theory is used to analyze the experimental crystal
structure, the Born charges, the elastic and piezoelectric properties. The Born
charge tensor is correlated to the local bonding environment for each atom. The
electronic band structure is computed including self-consistent many-body
corrections. Al4SiC4 material properties are compared to other wide band gap
W\"urtzite materials. From a comparison between an ellipsometry study of the
optical properties and theoretical results, we conclude that the Al4SiC4
material has indirect and direct band gap energies of about 2.5eV and 3.2 eV
respectively.Comment: 10 pages, 4 figure
SiC bulk growth processes: achievements and next challenges
Plenary talkInternational audienc
Initiation d'une " filière nitrures à grand gap " : croissance et caractérisation de cristaux massifs d'AlN pour les applications optoélectroniques
National audienc
Growth of Ti3SiC2 single crystals
Symposium 12: Materials for Extreme EnvironmentsInternational audienc
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