Qiufeng Yang¹, Xudong Li², Zhaowei Liu³, Feng Jin^1,*, Yilin Qu^1,*

The International Conference on Computational & Experimental Engineering and Sciences, Vol.26, No.3, pp. 1-2, 2023, DOI:10.32604/icces.2023.09073

Abstract Compared to piezoelectric effects restricted to noncentrosymmetric crystalline structures, flexoelectric effects exist universally in all crystalline structures [1,2]. Meanwhile, some crystals, say silicon, are also semiconductive, which raises interest in studying the interactions between mechanical fields and mobile charges in semiconductors with consideration of piezoelectricity or flexoelectricity [3,4]. In order to explain these coupling effects, macroscopic theories on elastic semiconductors considering piezoelectricity or flexoelectricity were proposed by Yang and co-authors [5,6]. For piezoelectric semiconductors, the formulation of finite elements is relatively straightforward since the governing partial derivative equation (PDE) is twice-order. As for elastic semiconductors with consideration of flexoelectricity, it… More >

Fang Liu¹, Yonghui You², Min Wang^1,*

FDMP-Fluid Dynamics & Materials Processing, Vol.18, No.6, pp. 1827-1839, 2022, DOI:10.32604/fdmp.2022.019132

Abstract CoSbS-based compounds are good thermoelectric materials with low thermal conductivity and good electrical properties, which can effectively be used to improve the efficiency of many thermoelectric conversion processes. In order to improve their properties even more, in this study a series of experiments have been conducted in the frame of the traditional solid-phase synthesis and high-pressure method. It is shown that if the mass fluctuation and stress fluctuation in the considered CoSbS system increase, the scattering probability of phonons is enhanced and the lattice thermal conductivity of the material is reduced. Adding a small amount of Se can simultaneously optimize… More >

Ismail M. Taye¹, Kh. Lotfy^2,4,*, A. A. El-Bary^3,5, Jawdat Alebraheem¹, Sadia Asad¹

CMC-Computers, Materials & Continua, Vol.67, No.3, pp. 3601-3618, 2021, DOI:10.32604/cmc.2021.015223

Abstract A novel model of a hyperbolic two-temperature theory is investigated to study the propagation the thermoelastic waves on semiconductor materials. The governing equations are studied during the photo-excitation processes in the context of the photothermal theory. The outer surface of o semiconductor medium is illuminated by a laser pulse. The generalized photo-thermoelasticity theory in two dimensions (2D) deformation is used in many models (Lord–Shulman (LS), Green–Lindsay (GL) and the classical dynamical coupled theory (CD)). The combinations processes between the hyperbolic two-temperature theory and photo-thermoelasticity theory under the effect of laser pulses are obtained analytically. The harmonic wave technique is used… More >

B. Yang², V. K. Tewary³

CMES-Computer Modeling in Engineering & Sciences, Vol.15, No.3, pp. 165-178, 2006, DOI:10.3970/cmes.2006.015.165

Abstract Green's function (GF) modeling of defects may take effect only if the GF as well as its various integrals over a line, a surface and/or a volume can be efficiently evaluated. The GF is needed in modeling a point defect, while integrals are needed in modeling line, surface and volumetric defects. In a matrix of multilayered, generally anisotropic and linearly elastic and piezoelectric materials, the GF has been derived by applying 2D Fourier transforms and the Stroh formalism. Its use involves another two dimensions of integration in the Fourier inverse transform. A semi-analytical scheme has been developed previously for efficient… More >

Mei-Jiau Huang¹, Tung-Chun Tsai¹, Liang-Chun Liu^1,2, Ming-shan Jeng², Chang-Chung Yang²

CMES-Computer Modeling in Engineering & Sciences, Vol.42, No.2, pp. 107-130, 2009, DOI:10.3970/cmes.2009.042.107

Abstract We develop a Monte-Carlo simulator for phonon transport in nanostructured semiconductors, which solves the phonon Boltzmann transport equation under the gray medium approximation. Proper physical models for the phonon transmission/reflection at an interface between two different materials and proper numerical boundary conditions are designed and implemented carefully. Most of all, we take advantage of geometric symmetry that exists in a system to reduce the computational amount. The validity and accuracy of the proposed MC solver was successfully verified via a 1D transient conduction problem and the cross-plane (1D) and in-plane (2D) phonon transport problems associated with Si/Ge superlattice thin films. More >

C. J. F. Solano, A. Costales, E. Francisco, A. Martín Pendás, Miguel A. Blanco¹, K.-C. Lau, H. He, Ravindra Pandey²

CMES-Computer Modeling in Engineering & Sciences, Vol.24, No.2&3, pp. 143-156, 2008, DOI:10.3970/cmes.2008.024.143

Abstract The buckling of hexagonal layers in bulk and nanostructures of AlN is analyzed in the framework of atomistic and first principles techniques. At ambient conditions, the wurtzite structure (B4) of AlN consists of buckled hexagons. On the other hand, a non-buckled B_k structure is found to be metastable at zero pressure, being favored at higher pressures. It is suggested that the energy ordering of B4 and B_k may change in finite systems; an assertion tested in this study by considering finite slabs, nanobelts, and nanorings, and comparing the results with the previous studies on small clusters, and periodic nanostructures. We… More >

Morteza Eslamian^1,2, M. Ziad Saghir^1,3

FDMP-Fluid Dynamics & Materials Processing, Vol.8, No.4, pp. 353-380, 2012, DOI:10.3970/fdmp.2012.008.353

Abstract In this paper recent advances pertinent to the applications of thermodiffusion or thermomigration in the fabrication of micro and nano metal-doped semiconductor-based patterns and devices are reviewed and discussed. In thermomigration, a spot, line, or layer of a p-type dopant, such as aluminum, which is deposited on a semiconductor surface, penetrates into the semiconductor body due to the presence of a temperature gradient applied across the wafer body. The trails of p-doped regions within an n-type semiconductor, in the form of columns or walls, may be used for several applications, such as the isolation of a part of a semiconductor… More >