Effects of vacancy defects and axial strain on thermal conductivity of silicon nanowires: A reverse nonequilibrium molecular dynamics simulation

Shahraki, Mehran Gholipour; Zeinali, Zahra

doi:10.1016/j.jpcs.2015.06.001

Cited by 21 publications

(9 citation statements)

References 50 publications

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“…More importantly we notice that the general trend of κ(ε h ) variations obtained with Tersoff III potential, plotted in Fig. 2, is similar to the previously reported strain effects on the thermal conductivity of bulk silicon 7,11,15 and Si nanostructures 64,65 .…”

Section: Resultssupporting

confidence: 88%

Thermal conductivity of strained silicon: Molecular dynamics insight and kinetic theory approach

Kuryliuk

Nepochatyi

Chantrenne

et al. 2019

Journal of Applied Physics

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In this work, we investigated tensile and compression forces effect on the thermal conductivity of silicon. We used equilibrium molecular dynamics approach for the evaluation of thermal conductivity considering different interatomic potentials. More specifically, we tested Stillinger-Weber, Tersoff, Environment-Dependent Interatomic Potential and Modified Embedded Atom Method potentials for the description of silicon atom motion under different strain and temperature conditions. It was shown that Tersoff potential gives a correct trend of thermal conductivity with hydrostatic strain, while other potentials fails, especially when compression strain is applied. Additionally, we extracted phonon density of states and dispersion curves from molecular dynamics simulations. These data were used for direct calculations of thermal conductivity considering the kinetic theory approach. Comparison of molecular dynamics and kinetic theory simulations results as a function of strain and temperature allowed us to investigate the different factors affecting the thermal conductivity of strained silicon.

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Section: Resultssupporting

confidence: 88%

Thermal conductivity of strained silicon: Molecular dynamics insight and kinetic theory approach

Kuryliuk

Nepochatyi

Chantrenne

et al. 2019

Journal of Applied Physics

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“…The field of application of SiNWs is vast and therefore a huge amount of research has been done about its production, sustainability and the improvement of its applicability. Due to the superior thermoelectric, electric, optical and thermal properties, SiNW field effect transistors (SiNW‐FETs) are used as highly responsive biosensors [1]. SiNWs are used as anodes in lithium ion rechargeable batteries, in photovoltaic devices, in thermoelectric devices [2] and in electronic devices to overcome the heating issue.…”

Section: Introductionmentioning

confidence: 99%

“…The TC of SiNWs is affected by various factors such as its geometry, like the length, cross‐sectional shape and radius, external factors such as temperature and the strain and the direction of the strain, and the inclusion of defects and infiltration by impurities. Altering any of the above factors can alter the value of TC as well, whether it is structural defects due to incorrect growth processes or intentional modification by addition of defects or impurities or by surface decoration done to enhance the thermoelectric capacity [1]. The thermal properties of nanoscale structures vary significantly from their bulk counterparts.…”

Section: Introductionmentioning

confidence: 99%

Effects of vacancy defects location on thermal conductivity of silicon nanowire: a molecular dynamics study

Meem

Chowdhury

Morshed

2018

Micro & Nano Letters

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The improvement of thermoelectric figure of merit of silicon nanowire (SiNW) can be achieved by lowering its thermal conductivity. In this work, non-equilibrium molecular dynamics method was used to demonstrate that the thermal conductivity of bulk silicon crystal is drastically reduced when it is crafted as SiNW and that it can be reduced remarkably by including vacancy defects. It has been found that 'centre vacancy defect' contributes much more in reducing the thermal conductance than 'surface vacancy defect'. The lowest thermal conductivity that occurs is about 52.1% of that of pristine SiNW, when 2% vacancy defect is introduced in the nanowire. The vibrational density of states analysis was performed to understand the nature of this reduction and it has been found that the various boundary scatterings of phonon significantly reduce the thermal conductivity. Also, larger mass difference due to voids induces smaller thermal conductivity values. These results indicate that the inclusion of vacancy defects can enhance the thermoelectric performance of SiNWs.

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“…By raising the percentage of random vacancy defects, linearly decreased TC of SiNWs is observed in the results obtained from SW potential, and non-linearly decreased TC is observed in the results based on Tersoff interatomic potential. It indicates that vacancy defects can promote the efficiency of thermoelectric energy conversion of SiNWs (Shahraki and Zeinali, 2015). A simulation conducted by Zhan et al (2014) indicated that the stacking faults can greatly reduce the TC of the SiNW, and the extrinsic stacking faults can induce a larger reduction than the twin boundary and intrinsic stacking faults.…”

Section: Introductionmentioning

confidence: 99%

Molecular Dynamics Simulations on Influence of Defect on Thermal Conductivity of Silicon Nanowires

Rui

Wang

et al. 2021

Front. Energy Res.

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A non-equilibrium molecular dynamics simulation method is conducted to study the thermal conductivity (TC) of silicon nanowires (SiNWs) with different types of defects. The impacts of defect position, porosity, temperature, and length on the TC of SiNWs are analyzed. The numerical results indicate that SiNWs with surface defects have higher TC than SiNWs with inner defects, the TC of SiNWs gradually decreases with the increase of porosity and temperature, and the impact of temperature on the TC of SiNWs with defects is weaker than the impact on the TC of SiNWs with no defects. The TC of SiNWs increases as their length increases. SiNWs with no defects have the highest corresponding frequency of low-frequency peaks of phonon density of states; however, when SiNWs have inner defects, the lowest frequency is observed. Under the same porosity, the average phonon participation of SiNWs with surface defects is higher than that of SiNWs with inner defects.

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Effects of vacancy defects and axial strain on thermal conductivity of silicon nanowires: A reverse nonequilibrium molecular dynamics simulation

Cited by 21 publications

References 50 publications

Thermal conductivity of strained silicon: Molecular dynamics insight and kinetic theory approach

Thermal conductivity of strained silicon: Molecular dynamics insight and kinetic theory approach

Effects of vacancy defects location on thermal conductivity of silicon nanowire: a molecular dynamics study

Molecular Dynamics Simulations on Influence of Defect on Thermal Conductivity of Silicon Nanowires

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