Phonons and thermal transport in graphene and graphene-based materials

Nika, Denis L.; Balandin, Alexander A.

doi:10.1088/1361-6633/80/3/036502

Cited by 303 publications

(222 citation statements)

References 167 publications

(543 reference statements)

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“…[68,[70][71][72][73][74][75][76] The first studies showed that adding even a small loading fraction of the optimized mixture of graphene and FLG (up to f = 10 vol%) to the pristine epoxy increases its thermal conductivity by a factor of ×25. [86] Prior studies suggested that the graphene-based composite exhibits the "electrical percolation threshold" at rather low loading fractions of graphene or FLG fillers. [77,78] One of the conclusions from the reports of the thermal properties of composites with graphene and FLG is that there exists an optimum range of the filler lateral dimensions, thicknesses, and aspect ratios for heat conduction.…”

Section: Introductionmentioning

confidence: 99%

Dual‐Functional Graphene Composites for Electromagnetic Shielding and Thermal Management

Kargar

Barani

Balinskiy

et al. 2018

Adv Elect Materials

201

132

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and environment. [12][13][14] The current industrial and safety standards require blocking of more than 99% of the EM radiation from any electronic devices. [1,[15][16][17] From the other side, the operation of the electronic devices can be disrupted by the outside EM waves. The heat and EM radiation have an inherent connection-absorption of EM waves by any material results in its heating. The energy from EM wave transfers to electrons and then to phonons-quanta of crystal lattice vibrations. The conventional approach for handling the heat and EM radiation problems is based on utilization of the thermal interface materials (TIM), which can spread the heat, and electromagnetic interference (EMI) shielding materials, which can protect from EM waves. These two types of materials have different, and, often, opposite characteristics, e.g., excellent EMI material can be a poor heat conductor, while efficient TIM can utilize electrically nonconductive fillers, resulting in its transparency for EM waves. Here, we propose a concept of the "dual-functional" EMI shielding-TIM materials, and demonstrate it on the example of graphene composites.It is well known that EMI shielding requires interaction of the EM waves with the charge carriers inside the material so that EM radiation is reflected or absorbed. For this reason, the EMI shielding material must be electrically conductive or contain electrically conductive fillers, although a high electrical conductivity is not required. The bulk electrical resistivity on the order of 1 Ω cm is sufficient for most of EMI shielding applications. [1,3,15] Most of the polymer-based materials widely used as TIMs in electronic packaging are electrically insulating and, therefore, transmit EM waves. Conventionally, metal particles are added as fillers in high volume fractions to the base polymer matrix in order to increase the electrical conductivity and prevent EM wave propagation from the device to the environment and vice versa. [1,[18][19][20][21] However, the polymer-metal composites suffer from high weight, cost, and corrosion, which make them an undesirable choice for the state-of-the-art downscaled electronics. Several studies reported the use of carbon fibers, [22][23][24][25][26][27][28][29] carbon black, [30,31] bulk graphite, [32][33][34] carbon nanotubes (CNT), [16,17,[35][36][37][38][39] reduced graphene oxide (rGO), [2,6,[40][41][42][43][44][45][46][47][48][49][50] graphene, [51][52][53][54] and combination of carbon allotropes with orThe synthesis and characterization of epoxy-based composites with few-layer graphene fillers, which are capable of dual-functional applications, are reported. It is found that composites with certain types of few-layer graphene fillers reveal an efficient total electromagnetic interference shielding, SE tot ≈ 45 dB, in the important X-band frequency range, f = 8.2 −12.4 GHz, while simultaneously providing high thermal conductivity, K ≈ 8 W m −1 K −1 , which is a factor of ×35 larger than that of the base matrix material. The efficiency of the d...

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Section: Introductionmentioning

confidence: 99%

Dual‐Functional Graphene Composites for Electromagnetic Shielding and Thermal Management

Kargar

Barani

Balinskiy

et al. 2018

Adv Elect Materials

201

132

View full text Add to dashboard Cite

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“…The increase in the thermal conductivity of the resulting composite can come owing to two possible mechanisms. The first one is related to very high intrinsic thermal conductivity of graphene [46] and its good coupling to the matrix materials [41,43,45]. The heat propagates partially via graphene fillers and partially via the matrix material.…”

Section: Testing Of the Photovoltaic Solar Cellsmentioning

confidence: 99%

“…This material has proven to have an unusually high thermal conductivity with intrinsic values in the range of 2000 to 5000 W/mK near room temperature [46]. This is an order of magnitude larger than pure silver [33][34][35].…”

Section: Introductionmentioning

confidence: 99%

Thermal Management of Concentrated Multi-Junction Solar Cells with Graphene-Enhanced Thermal Interface Materials

2017

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Abstract:We report results of experimental investigation of temperature rise in concentrated multi-junction photovoltaic solar cells with graphene-enhanced thermal interface materials. Graphene and few-layer graphene fillers, produced by a scalable environmentally-friendly liquid-phase exfoliation technique, were incorporated into conventional thermal interface materials. Graphene-enhanced thermal interface materials have been applied between a solar cell and heat sink to improve heat dissipation. The performance of the multi-junction solar cells has been tested using an industry-standard solar simulator under a light concentration of up to 2000 suns. It was found that the application of graphene-enhanced thermal interface materials allows one to reduce the solar cell temperature and increase the open-circuit voltage. We demonstrated that the use of graphene helps in recovering a significant amount of the power loss due to solar cell overheating. The obtained results are important for the development of new technologies for thermal management of concentrated photovoltaic solar cells.

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“…It is also worth noting that this technique is the only option without extensive nanofabrication for two‐dimensional materials. In the previous studies, for measuring the thermal conductivity of two‐dimensional materials with Raman thermal technique, the sample was usually suspended over a trench and heated by increasing laser power . According to the heat conduction through the sample surface, the thermal conductivity values could be extracted on the basis of Fourierapos;s equation as:

K = χ_{G} \frac{L}{2 S} ((), \frac{italicdP}{italicdω}),

where K is the thermal conductivity, χ G is the temperature coefficient, L is the distance from the middle of the suspended sample to the heat sink, S is the cross‐sectional area, and dω is a peak shift due to the variation dP in the heating power on the sample surface.…”

Section: Iintroductionmentioning

confidence: 99%

“…In the previous studies, for measuring the thermal conductivity of two-dimensional materials with Raman thermal technique, the sample was usually suspended over a trench and heated by increasing laser power. [4][5][6][7][8][9][10] According to the heat conduction through the sample surface, the thermal conductivity values could be extracted on the basis of Fourier's equation as [10] :…”

Section: Iintroductionmentioning

confidence: 99%

Determination of thermal conductivity using micro‐Raman spectroscopy with a three‐dimensional heating model

Cao

2019

J Raman Spectroscopy

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The thermal conductivity of isotropic graphite was investigated using Raman spectroscopy technique. In this method, the Raman laser acted simultaneously as an excitation source and a heating source. The dependences of the Raman peak position on temperature and laser power for the isotropic graphite were analyzed to establish Raman thermometry. Meanwhile, the local temperature rise induced by the laser irradiation was also theoretically described using a three‐dimensional heating model, which can be related to the thermal conductivity. The laser absorptivity, the spot size, and the probing volume of Raman spectra were discussed, respectively. Besides, simulations of the localized temperature distribution were performed. On the basis of the Raman thermometry and the three‐dimensional heating model, the thermal conductivity of 55 W/m K for the isotropic graphite was estimated, which was comparable with the value (60 W/m K) obtained by the laser flash technique.

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Phonons and thermal transport in graphene and graphene-based materials

Cited by 303 publications

References 167 publications

Dual‐Functional Graphene Composites for Electromagnetic Shielding and Thermal Management

Dual‐Functional Graphene Composites for Electromagnetic Shielding and Thermal Management

Thermal Management of Concentrated Multi-Junction Solar Cells with Graphene-Enhanced Thermal Interface Materials

Determination of thermal conductivity using micro‐Raman spectroscopy with a three‐dimensional heating model

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