Thermal Conductivity Measurement of Graphene Exfoliated on Silicon Dioxide

2010 ◽  
Author(s):  
Jae Hun Seol ◽  
Arden L. Moore ◽  
Insun Jo ◽  
Zhen Yao ◽  
Li Shi
Keyword(s):  
Thermal Conductivity ◽  
Silicon Dioxide ◽  
Thermal Transport ◽  
Heat Dissipation ◽  
Electronic Materials ◽  
Conductivity Measurement ◽  
Heat Transfer Analysis ◽  
Suspended Graphene ◽  
Numerical Heat Transfer ◽  
Low Dimensional

Since graphene was first exfoliated from graphite, the monatomic layer of carbon atoms has attracted great interest for fundamental studies of unique two dimensional transport phenomena. Meanwhile, graphene is being explored for nanoelectronic applications because of the superior electron mobility and mechanical strength as well as compatibility with existing planar silicon-based microelectronics. The ultrahigh thermal conductivity suggested recently for suspended graphene is another attractive feature that may potentially address the increasingly severe heat dissipation problems in nanoelectronic devices. However, little is known about thermal transport properties of supported graphene that is used in most graphene device configurations. To better understand thermal transport in supported graphene, we have developed a device to measure the thermal conductivity of graphene exfoliated on a silicon dioxide beam. The obtained peak thermal conductivity is about 600 W/m-K near room temperature. This value is lower than the basal plane values for graphite and suspended graphene, but still considerably higher than common electronic materials. The measurement results at low temperatures further reveal intriguing low dimensional behaviors. Here, we present a detailed analytical and numerical heat transfer analysis of the thermal measurement method.

Thermal Conductivity Measurement of Graphene Exfoliated on Silicon Dioxide

2010 ◽  
Vol 133 (2) ◽  
Author(s):  
Jae Hun Seol ◽  
Arden L. Moore ◽  
Li Shi ◽  
Insun Jo ◽  
Zhen Yao
Keyword(s):  
Thermal Conductivity ◽  
Silicon Dioxide ◽  
Ultrathin Films ◽  
Room Temperature ◽  
Electronic Materials ◽  
Conductivity Measurement ◽  
Thermal Conductivity Measurement ◽  
Resistance Thermometer ◽  
Numerical Heat Transfer ◽  
Measurement Results

We have developed a nanofabricated resistance thermometer device to measure the thermal conductivity of graphene monolayers exfoliated onto silicon dioxide. The measurement results show that the thermal conductivity of the supported graphene is approximately 600 W/m K at room temperature. While this value is lower than the reported basal plane values for graphite and suspended graphene because of phonon leakage across the graphene-support interface, it is still considerably higher than the values for common thin film electronic materials. Here, we present a detailed discussion of the design and fabrication of the measurement device. Analytical and numerical heat transfer solutions are developed to evaluate the accuracy and uncertainty of this method for thermal conductivity measurement of high-thermal conductivity ultrathin films.

scholarly journals The Kirchhoff Transformation for Convective-radiative Thermal Problemsin Fins

2021 ◽  
Vol 15 ◽  
pp. 12-21
Author(s):  
Jonatas Motta Quirino ◽  
Eduardo Dias Correa ◽  
Rodolfo do Lago Sobral
Keyword(s):  
Thermal Conductivity ◽  
Boundary Conditions ◽  
Thermal Radiation ◽  
Heat Dissipation ◽  
Variable Thermal Conductivity ◽  
Dirichlet Boundary Conditions ◽  
Heat Transfer Analysis ◽  
Temperature Function ◽  
Kirchhoff Transformation ◽  
Comparison Of The Results

- The present work describes the thermal profile of a single dissipation fin, where their surfaces reject heat to the environment. The problem happens in steady state, which is, all the analysis occurs after the thermal distribution reach heat balance considering that the fin dissipates heat by conduction, convection and thermal radiation. Neumann and Dirichlet boundary conditions are established, characterizing that heat dissipation occurs only on the fin faces, in addition to predicting that the ambient temperature is homogeneous. Heat transfer analysis is performed by computational simulations using appropriate numerical methods. The most of solutions in the literature consider some simplifications as constant thermal conductivity and linear boundary conditions, this work addresses this subject. The method applied is the Kirchhoff Transformation, that uses the thermal conductivity variation to define the temperatures values, once the thermal conductivity variate as a temperature function. For the real situation approximation, this work appropriated the silicon as the fin material to consider the temperature function at each point, which makes the equation that governs the non-linear problem. Finally, the comparison of the results obtained with typical results proves that the assumptions of variable thermal conductivity and heat dissipation by thermal radiation are crucial to obtain results that are closer to reality.

scholarly journals Tuning the Anisotropic Thermal Transport in {110}-Silicon Membranes with Surface Resonances

Nanomaterials ◽  
2021 ◽  
Vol 12 (1) ◽  
pp. 123
Author(s):  
Keqiang Li ◽  
Yajuan Cheng ◽  
Maofeng Dou ◽  
Wang Zeng ◽  
Sebastian Volz ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Thermal Transport ◽  
Heat Dissipation ◽  
Mean Free Path ◽  
Dynamic Simulations ◽  
Resonant Structures ◽  
Thermoelectric Energy ◽  
Thin Membranes ◽  
The Mean ◽  
Equilibrium Molecular Dynamic

Understanding the thermal transport in nanostructures has important applications in fields such as thermoelectric energy conversion, novel computing and heat dissipation. Using non-homogeneous equilibrium molecular dynamic simulations, we studied the thermal transport in pristine and resonant Si membranes bounded with {110} facets. The break of symmetry by surfaces led to the anisotropic thermal transport with the thermal conductivity along the [110]-direction to be 1.78 times larger than that along the [100]-direction in the pristine structure. In the pristine membranes, the mean free path of phonons along both the [100]- and [110]-directions could reach up to ∼100 µm. Such modes with ultra-long MFP could be effectively hindered by surface resonant pillars. As a result, the thermal conductivity was significantly reduced in resonant structures, with 87.0% and 80.8% reductions along the [110]- and [100]-directions, respectively. The thermal transport anisotropy was also reduced, with the ratio κ110/κ100 decreasing to 1.23. For both the pristine and resonant membranes, the thermal transport was mainly conducted by the in-plane modes. The current work could provide further insights in understanding the thermal transport in thin membranes and resonant structures.

Numerical Heat Transfer Model of Buried Pipe and Ground Thermal Conductivity Measurement

2011 ◽  
Vol 99-100 ◽  
pp. 112-115
Author(s):  
Ming Zhi Yu ◽  
Lei Zhang ◽  
Xiao Fei Yu ◽  
Zhao Hong Fang
Keyword(s):  
Heat Transfer ◽  
Thermal Conductivity ◽  
Estimation Method ◽  
Conductivity Measurement ◽  
Heat Transfer Model ◽  
Parameters Estimation ◽  
Transfer Model ◽  
Buried Pipe ◽  
Geothermal Heat ◽  
Numerical Heat Transfer

A two dimensional numerical heat transfer model of buried geothermal heat exchanger has been established by finite element method. This model is used to analyse the heat transfer between buried vertical pipes and the ground, and determine the ground thermal properties together with parameters estimation method. The ground thermal conductivity of an actual project was measured and the analysis shows that the results can be used for engineering design.

Thermal Transport in Nanostructured Solid-State Cooling Devices

2005 ◽  
Vol 127 (1) ◽  
pp. 108-114 ◽  
Author(s):  
Deyu Li ◽  
Scott T. Huxtable ◽  
Alexis R. Abramson ◽  
Arun Majumdar
Keyword(s):  
Thermal Conductivity ◽  
Solid State ◽  
Nanostructured Materials ◽  
Thermal Transport ◽  
Experimental Studies ◽  
Phonon Transport ◽  
Peltier Effect ◽  
Cooling Devices ◽  
Low Dimensional ◽  
Solid State Cooling

Low-dimensional nanostructured materials are promising candidates for high efficiency solid-state cooling devices based on the Peltier effect. Thermal transport in these low-dimensional materials is a key factor for device performance since the thermoelectric figure of merit is inversely proportional to thermal conductivity. Therefore, understanding thermal transport in nanostructured materials is crucial for engineering high performance devices. Thermal transport in semiconductors is dominated by lattice vibrations called phonons, and phonon transport is often markedly different in nanostructures than it is in bulk materials for a number of reasons. First, as the size of a structure decreases, its surface area to volume ratio increases, thereby increasing the importance of boundaries and interfaces. Additionally, at the nanoscale the characteristic length of the structure approaches the phonon wavelength, and other interesting phenomena such as dispersion relation modification and quantum confinement may arise and further alter the thermal transport. In this paper we discuss phonon transport in semiconductor superlattices and nanowires with regards to applications in solid-state cooling devices. Systematic studies on periodic multilayers called superlattices disclose the relative importance of acoustic impedance mismatch, alloy scattering, and crystalline imperfections at the interfaces. Thermal conductivity measurements of mono-crystalline silicon nanowires of different diameters reveal the strong effects of phonon-boundary scattering. Experimental results for Si/SiGe superlattice nanowires indicate that different phonon scattering mechanisms may disrupt phonon transport at different frequencies. These experimental studies provide insight regarding the dominant mechanisms for phonon transport in nanostructures. Finally, we also briefly discuss Peltier coolers made from nanostructured materials that have shown promising cooling performance.

Molecular Dynamics Modeling of Heat Transport in Metals and Semiconductors

2010 ◽  
Author(s):  
Sreekant Narumanchi ◽  
Kwiseon Kim
Keyword(s):  
Experimental Data ◽  
Thermal Conductivity ◽  
Molecular Dynamics ◽  
Thermal Transport ◽  
Hybrid Electric Vehicle ◽  
Heat Dissipation ◽  
Phonon Dispersion ◽  
Interfacial Resistance ◽  
Dynamics Modeling ◽  
Molecular Dynamics Modeling

Interfacial thermal transport is of great importance in a number of practical applications where interfacial resistance between layers is frequently a major bottleneck to effective heat dissipation. For example, efficient heat transfer at silicon/aluminum and silicon/copper interfaces is very critical in power electronics packages used in hybrid electric vehicle applications. It is therefore important to understand the factors that govern and impact thermal transport at semiconductor/metal interfaces. Hence, in this study, we use classical molecular dynamics modeling to understand and study thermal transport in silicon and aluminum, and some preliminary modeling to study thermal transport at the interface between silicon and aluminum. A good match is shown between our modeling results for thermal conductivity in silicon and aluminum and the experimental data. The modeling results from this study also match well with relevant numerical studies in the literature for thermal conductivity. In addition, preliminary modeling results indicate that the interfacial thermal conductance for a perfect silicon/aluminum interface is of the same order as experimental data in the literature as well as diffuse mismatch model results accounting for realistic phonon dispersion curves.

Thermal Conductivity of α-Tetragonal Boron Nanoribbons

2009 ◽  
Author(s):  
Scott W. Waltermire ◽  
Juekuan Yang ◽  
Deyu Li ◽  
Terry T. Xu
Keyword(s):  
Thermal Conductivity ◽  
Thermal Transport ◽  
Room Temperature ◽  
High Hardness ◽  
Mean Free Path ◽  
Good Oxidation Resistance ◽  
Elemental Boron ◽  
Past Half Century ◽  
Materials Research ◽  
Low Dimensional

Elemental boron has many interesting properties, such as high melting point, low density, high hardness, high Young’s modulus, good oxidation resistance, resulting from its complex crystalline structure from its electron-deficient nature. Boron forms complex crystalline structures according to the various arrangements of B12 icosahedra in the lattice, such as α (B12)- and β (B105)-rhombohedral and α (B50)- and β (B196)-tetragonal boron polymorphs, among others. Even though considerable materials research has been conducted over the past half century on boron and boron-based compounds, investigating their unique structures and corresponding properties, our understanding of this complex class of materials is still poor, compared to some other well-studied materials with much simpler structures such as silicon. Thermal transport studies through bulk boron have been performed mainly on β-rhombohedral and amorphous boron, because of the difficulty to grow high quality bulk α-rhombohedral boron samples [1–3]. Some efforts have been made to measure B12As2, B12P2, AlB12 samples that have an α-rhombohedral form [2,3]. There is almost no information available on α-tetragonal boron. However, Slack predicted the thermal conductivity of α-boron should be ∼200 W/m-K at room temperature, which is 1/2 that of copper. Large phonon mean free path has been predicted for α-boron (from ∼200 nm at room temperature to 6 nm at the Debye temperature), which could lead to interesting thermal transport properties for low dimensional boron structures.

scholarly journals A cross-interface model for thermal transport across the interface between overlapped nanoribbons

2019 ◽  
Vol 21 (45) ◽  
pp. 25072-25079 ◽  
Author(s):  
Wentao Feng ◽  
Xiaoxiang Yu ◽  
Yue Wang ◽  
Dengke Ma ◽  
Zhijia Sun ◽  
...  
Keyword(s):  
Composite Materials ◽  
Thermal Transport ◽  
Heat Dissipation ◽  
Electronic Devices ◽  
Interface Model ◽  
Comprehensive Understanding ◽  
The Cross ◽  
Low Dimensional ◽  
Low Dimensional Materials

The application of low-dimensional materials for heat dissipation requires a comprehensive understanding of thermal transport at the cross-interface, which widely exists in various composite materials and electronic devices.

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