Al4SiC4 wurtzite crystal: Structural, optoelectronic, elastic, and piezoelectric properties

Abstract

International audienceNew 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 properties, and the piezoelectricproperties. 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. Al4SiC4material properties are compared to other wide band gap wurtzite materials. From a comparison between an ellipsometry study of the optical properties and theoretical results, we conclude that the Al4SiC4material has indirect and direct band gapenergies of about 2.5 eV and 3.2 eV, respectively

A theoretical study of dielectric tensor, Born effective charges, LO-TO splitting and infrared response of Al4SiC4 and Al4Si2C5

“…Liao et al [11] investigated the bonding characteristics, atomic deformation modes and ideal mechanical strengths of Al 4 SiC 4 , it was concluded that the structural failure occurring in tensile deformation simulation is due to the existence of intrinsic brittleness in Al 4 SiC 4 . In a very recent work, Pedesseau and coworkers [12] have addressed the optoelectronic, elastic and piezoelectric properties of Al 4 SiC 4 . Most importantly, the authors employed the self-consistent many-body perturbation method to calculate the band gap of the same phase.…”

Al4SiC4 vibrational properties: density functional theory calculations compared to Raman and infrared spectroscopy measurements

“…The crystal structure of typical mm size Al 4 SiC 4 platelets was investigated by TEM observations and XRD analysis and reported to be hexagonal (Space group P6 3 mc), their c-axis being perpendicular to the crystal surface [6,10] …”

“…The local density approximation (LDA) was used for the exchange-correlation functional [23,24]. Atomic valence configurations were similar to the ones used in previous DFT simulations of the ground state [5,6,18]. A plane-wave basis set with an energy cut-off of 950 eV was used to expand the electronic wave-functions.…”

“…Among them, Al 4 SiC 4 is a low cost potential candidate for power electronics due to its highly desirable combination of unique physical properties such as high thermal conductivity and stability at high temperature [1][2][3][4] and promising semiconductor properties [5][6][7][8][9].…”

Synthesis of Al4SiC4 powders via carbothermic reduction: Reaction and grain growth mechanisms

“…6, Al 4 SiC 4 owns a P6 3 mc space group and a hexagonal crystal structure which can be described as layered structure stacked with the 4H-SiC type units and Al 4 C 3 type units alternative along the c-axis [35,36]. It has been reported that the development of the hexagonal grains depends on the grain growing rate of (0010) and (1 10) planes which is closely related to the surface energy.…”