Anomalous effect of hydrogenation on phonon thermal conductivity in thin silicon nanowires

Li, Haipeng; Zhang, Ruiqin

doi:10.1209/0295-5075/105/56003

Cited by 23 publications

(9 citation statements)

References 25 publications

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“…The PDOS of the perforated film and the crystalline film are close, while the PDOS of the amorphous film and amorphous perforated film are close. For the crystalline film, in accordance with previous studies [ 51 ], there is a strong peak at high frequency of 17 THz and a weak peak at low frequency of 5 THz. For the perforated silicon film, the reduction of atoms in the perforated region leads to a decrease in the peak and a shift to the left.…”

Section: Resultssupporting

confidence: 91%

Nanoscale Thermal Cloaking in Silicon Film: A Molecular Dynamic Study

Zhang¹,

Zhang²,

Sun³

et al. 2022

Materials

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Nanoscale thermal shielding is becoming increasingly important with the miniaturization of microelectronic devices. They have important uses in the field of thermal design to isolate electronic components. Several nanoscale thermal cloaks based on graphene and crystalline silicon films have been designed and experimentally verified. No study has been found that simultaneously treats the functional region of thermal cloak by amorphization and perforation methods. Therefore, in this paper, we construct a thermal cloak by the above methods, and the ratio of thermal cloaking and response temperature is used to explore its cloaking performance under constant and dynamic temperature boundary. We find that compared with the dynamic boundary, the cloaking effect produced under the constant boundary is more obvious. Under two temperature boundaries, the thermal cloak composed of amorphous and perforated has a better performance and has the least disturbance to the background temperature field. The phonon localization effect produced by the amorphous structure is more obvious than that of the perforated structure. The phonon localization of the functional region is the main reason for the cloaking phenomenon, and the stronger the phonon localization, the lower the thermal conductivity and the more obvious the cloaking effect. Our study extends the nanoscale thermal cloak construction method and facilitates the development of other nanoscale thermal functional devices.

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Section: Resultssupporting

confidence: 91%

Nanoscale Thermal Cloaking in Silicon Film: A Molecular Dynamic Study

Zhang¹,

Zhang²,

Sun³

et al. 2022

Materials

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“…Figure 7 shows the PDOS of the crystalline silicon film and the thermal cloak. For the crystalline silicon film, consistent with a previous study [65], a weak and a strong peak appeared at 5 THz and 17 THz, respectively. Phonons are generated due to the excitation of atomic vibration.…”

Section: Analysis Of Cloaking Mechanism Of Nanocloaksupporting

confidence: 91%

Thermal Cloaking in Nanoscale Porous Silicon Structure by Molecular Dynamics

Zhang

et al. 2022

Energies

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Nanoscale thermal cloaks have great potential in the thermal protection of microelectronic devices, for example, thermal shielding of thermal components close to the heat source. Researchers have used graphene, crystalline silicon film, and silicon carbide to design a variety of thermal cloaks in different ways. In our previous research, we found that the porous structure has lower thermal conductivity compared to bulk silicon; thus, so we tried to use the porous structure to construct the functional region to control the heat flux. We first calculated the thermal conductivity of crystalline silicon and porous silicon films by means of nonequilibrium molecular dynamics, proving that the porous structure satisfied the conditions for building a thermal cloak. A rectangular cloak with a porous structure was constructed, and a crystalline silicon film was used as a reference to evaluate its performance by the index of the ratio of thermal cloaking. We found that the thermal cloak built with a porous structure could produce an excellent cloaking effect. Lastly, we explain the mechanism of the cloaking phenomenon produced by a porous structure with the help of phonon localization theory. Porous structures have increased porosity compared to bulk silicon and are not conducive to phonon transport, thus producing strong phonon localization and reducing thermal conductivity. Our research expands the construction methods of nanocloaks, expands the application of porous structure materials, and provides a reference for the design of other nanodevices.

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“…4(a) that at a temperature of 100 K, the phonon PDOS of silicene and silicon is mainly distributed in the region of 0-20 THz, which is the same as that reported in previous studies. [42][43][44] Since the phonon frequency does not depend on the amplitude of the oscillations, the PDOS of harmonic systems should be temperature-independent. However, when the temperature increases to 400 K, it is observed that both the PDOS of silicene and a-Si become broader, which indicates that the umklapp scattering mechanism is dominant at this temperature range and the phonon anharmonicity is significant.…”

Section: Calculatedmentioning

confidence: 99%

Molecular dynamics study of interfacial thermal transport between silicene and substrates

Zhang

Yang

Tong

et al. 2015

Phys. Chem. Chem. Phys.

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In this work, the interfacial thermal transport across silicene and various substrates, i.e., crystalline silicon (c-Si), amorphous silicon (a-Si), crystalline silica (c-SiO2) and amorphous silica (a-SiO2) are explored by classical molecular dynamics (MD) simulations. A transient pulsed heating technique is applied in this work to characterize the interfacial thermal resistance in all hybrid systems. It is reported that the interfacial thermal resistances between silicene and all substrates decrease nearly 40% with temperature from 100 K to 400 K, which is due to the enhanced phonon couplings from the anharmonicity effect. Analysis of phonon power spectra of all systems is performed to interpret simulation results. Contradictory to the traditional thought that amorphous structures tend to have poor thermal transport capabilities due to the disordered atomic configurations, it is calculated that amorphous silicon and silica substrates facilitate the interfacial thermal transport compared with their crystalline structures. Besides, the coupling effect from substrates can improve the interface thermal transport up to 43.5% for coupling strengths χ from 1.0 to 2.0. Our results provide fundamental knowledge and rational guidelines for the design and development of the next-generation silicene-based nanoelectronics and thermal interface materials.

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Anomalous effect of hydrogenation on phonon thermal conductivity in thin silicon nanowires

Cited by 23 publications

References 25 publications

Nanoscale Thermal Cloaking in Silicon Film: A Molecular Dynamic Study

Nanoscale Thermal Cloaking in Silicon Film: A Molecular Dynamic Study

Thermal Cloaking in Nanoscale Porous Silicon Structure by Molecular Dynamics

Molecular dynamics study of interfacial thermal transport between silicene and substrates

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