Abstract
The structural, mechanical, anisotropic, and thermal properties of oC12-AlAs and hP6-AlAs under pressure have been investigated by employing first-principles calculations based on density functional theory. The elastic constants, bulk modulus, shear modulus, Young’s modulus, B/G ratio, and Poisson’s ratio for oC12-AlAs and hP6-AlAs have been systematically investigated. The results show that oC12-AlAs and hP6-AlAs are mechanically stable within the considered pressure. Through the study of lattice constants (a, b, and c) with pressure, we find that the incompressibility of oC12-AlAs and hP6-AlAs is the largest along the c-axis. At 0 GPa, the bulk modulus B of oC12-AlAs, hP6-AlAs, and diamond-AlAs are 76 GPa, 75 GPa, and 74 Gpa, respectively, indicating that oC12-AlAs and hP6-AlAs have a better capability of resistance to volume than diamond-AlAs. The pressure of transition from brittleness to ductility for oC12-AlAs and hP6-AlAs are 1.21 GPa and 2.11 GPa, respectively. The anisotropy of Young’s modulus shows that oC12-AlAs and hP6-AlAs have greater isotropy than diamond-AlAs. To obtain the thermodynamic properties of oC12-AlAs and hP6-AlAs, the sound velocities, Debye temperature, and minimum thermal conductivity at considered pressure were investigated systematically. At ambient pressure, oC12-AlAs (463 K) and hP6-AlAs (471 K) have a higher Debye temperature than diamond-AlAs (433 K). At T = 300 K, hP6-AlAs (0.822 W/cm·K−1) has the best thermal conductivity of the three phases, and oC12-AlAs (0.809 W/cm·K−1) is much close to diamond-AlAs (0.813 W/cm·K−1).
Highlights
Group III–V compound semiconductor materials are the “core” of solid-state light sources and power electronic devices because of their large band gap, high breakdown field, high thermal conductivity, high saturated electron drift velocity, strong radiation resistance, and superior performance [1,2,3,4,5,6,7]
GaN, AlN, AlP, and AlAs have been of considerable interest, because understanding their structural and electronic properties is crucial to semiconductor technological applications
First-principles calculations based on density functional theory (DFT) represent one of the most accurate microscopic theories in materials science
Summary
Group III–V compound semiconductor materials are the “core” of solid-state light sources and power electronic devices because of their large band gap, high breakdown field, high thermal conductivity, high saturated electron drift velocity, strong radiation resistance, and superior performance [1,2,3,4,5,6,7] They have broad application prospects in semiconductor lighting, new generation mobile communications, energy Internet, high-speed rail transportation, new energy vehicles, consumer electronics, and other fields, and it is hoped that these materials will break through the bottleneck of traditional semiconductor technology [8,9,10,11,12]. Using the CALYPSO (Crystal structure AnaLYsis by Particle Swarm Optimization) code, Liu et al [17] investigated four novel AlN phases (Pmn21 -AlN, Pbam-AlN, Pbca-AlN, and Cmcm-AlN), and proved that these four novel AlN phases are more favorable in thermodynamics than the rock-salt structure at ambient pressure, and can be transformed to the rock-salt structure under certain pressures
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
