Si–Ge alloys in C2/c phase with tunable direct band gaps: A comprehensive study

Fan, Qingyang; Wang, Huiqin; Zhang, Wenzhu; Mingfei, Wei; Song, Yanxing; Zhang, Wei; Yun, Sining

doi:10.1016/j.cap.2019.08.019

Cited by 17 publications

(18 citation statements)

References 38 publications

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“…Here, v i is the compressional or shear sound wave velocity, Θ i is the cut-off frequency for each polarization expressed in K, Θ i = v i [ h /(2π k B )](6π 2 n ) 1/3 and T is the temperature. This empirical formula has been used to predict the thermal conductivity of various materials [55,56,57]. The relations between the minimum thermal conductivity κ min and the temperature (from 0 to 1000 K) of all the materials studied in this work are illustrated in Figure 6.…”

Section: Resultsmentioning

confidence: 99%

Electronic, Mechanical and Elastic Anisotropy Properties of X-Diamondyne (X = Si, Ge)

et al. 2019

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The three-dimensional (3D) diamond-like semiconductor materials Si-diamondyne and Ge-diamondyne (also called SiC4 and GeC4) are studied utilizing density functional theory in this work, where the structural, elastic, electronic and mechanical anisotropy properties along with the minimum thermal conductivity are considered. SiC4 and GeC4 are semiconductor materials with direct band gaps and wide band gaps of 5.02 and 5.60 eV, respectively. The Debye temperatures of diamondyne, Si- and Ge-diamondyne are 422, 385 and 242 K, respectively, utilizing the empirical formula of the elastic modulus. Among these, Si-diamondyne has the largest mechanical anisotropy in the shear modulus and Young’s modulus, and Diamond has the smallest mechanical anisotropy in the Young’s modulus and shear modulus. The mechanical anisotropy in the Young’s modulus and shear modulus of Si-diamondyne is more than three times that of diamond as determined by the characterization of the ratio of the maximum value to the minimum value. The minimum thermal conductivity values of Si- and Ge-diamondyne are 0.727 and 0.524 W cm−1 K−1, respectively, and thus, Si- and Ge-diamondyne may be used in the thermoelectric industry.

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Section: Resultsmentioning

confidence: 99%

Electronic, Mechanical and Elastic Anisotropy Properties of X-Diamondyne (X = Si, Ge)

et al. 2019

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“…[8][9][10][11] Other theoretical results were obtained by replacing atoms in direct gap Si metastable phases with Ge atoms, which may suffer stability issues in ambient environment. [12][13][14][15] In this work, the particle swarm optimization (PSO) algorithm implemented in CALYPSO 16,17 is used to search direct band SiGe alloys in the range from Si 1 Ge 4 to Si 4 Ge 1 without external pressure. Three direct gap structures are found, two of which have the composition Si 3 Ge 2 while the other is Si 4 Ge 1 .…”

Section: Introductionmentioning

confidence: 99%

“…8–11 Other theoretical results were obtained by replacing atoms in direct gap Si metastable phases with Ge atoms, which may suffer stability issues in ambient environment. 12–15…”

Section: Introductionmentioning

confidence: 99%

A new direct band gap Si–Ge allotrope with advanced electronic and optical properties

Shen

Yang

Zhou

et al. 2022

Phys. Chem. Chem. Phys.

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“…The investigation leads to a tunable band gap that stems from the research of photonic crystal (Yablonovitch, 1987). Some investigations of the tunable band gap focused on the photonic crystal or phononic crystal (Fan et al, 2019; Li et al, 2020; Shkunov et al, 2002). Various wave guides were designed to control the wave propagation or tune the band gap (Airoldi and Ruzzene, 2011; Grinberg et al, 2018; Harrison et al, 2019; Zhou et al, 2019).…”

Section: Introductionmentioning

confidence: 99%

Tunable band gaps of axially moving belt on periodic elastic foundation

Lü¹

2022

Journal of Vibration and Control

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The present paper investigates the band structure of an axially moving belt resting on a foundation with periodically varying stiffness. It is concluded that the band gaps appear when the divergence of the eigenvalue occurs and the veering phenomenon of mode shape begins. The bifurcation of eigenvalues and mode shape veering lead to wave attenuation. Hence, the boundary stiffness modulation can be designed to manipulate the band gap where the vibration is suppressed. The contribution of the system parameters to the band gaps has been obtained by applying the method of varying amplitudes. By tuning the stiffness, the desired band gap can be obtained and the vibration for specific parameters can be suppressed. The current study provides a technique to avoid vibration transmission of the axially moving material by designing the foundation stiffness.

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Si–Ge alloys in C2/c phase with tunable direct band gaps: A comprehensive study

Cited by 17 publications

References 38 publications

Electronic, Mechanical and Elastic Anisotropy Properties of X-Diamondyne (X = Si, Ge)

Electronic, Mechanical and Elastic Anisotropy Properties of X-Diamondyne (X = Si, Ge)

A new direct band gap Si–Ge allotrope with advanced electronic and optical properties

Tunable band gaps of axially moving belt on periodic elastic foundation

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