Effects of multilayered graphene on the performance of near-field thermophotovoltaic system at longer vacuum gap distances

2017 ◽  
Vol 197 ◽  
pp. 84-94 ◽  
Author(s):  
Mikyung Lim ◽  
Seung S. Lee ◽  
Bong Jae Lee
Keyword(s):  
Near Field ◽  
Vacuum Gap

scholarly journals Probing the Hydrogen Enhanced Near-Field Emission of ITO without a Vacuum-Gap

2017 ◽  
Vol 7 (1) ◽  
Author(s):  
Jacob L. Poole ◽  
Yang Yu ◽  
Paul R. Ohodnicki
Keyword(s):  
Field Emission ◽  
Near Field ◽  
Vacuum Gap

Near-Field Radiation Calculated With an Improved Dielectric Function Model for Doped Silicon

2008 ◽  
Author(s):  
S. Basu ◽  
B. J. Lee ◽  
Z. M. Zhang
Keyword(s):  
Energy Transfer ◽  
Dielectric Function ◽  
Near Field ◽  
Silicon Surfaces ◽  
Function Model ◽  
Fluctuation Dissipation ◽  
Doped Silicon ◽  
Energy Conversion Systems ◽  
Field Radiation ◽  
Vacuum Gap

This paper describes a theoretical investigation of near-field radiative heat transfer between doped silicon surfaces separated by a vacuum gap. Using an improved dielectric function model for heavily doped silicon, along with fluctuation-dissipation theorem, and dyadic Green’s function, the present authors calculated the energy transfer between the doped silicon surfaces near room temperature. The effects of doping level, polarization, and width of the vacuum gap on the overall radiative transfer were investigated. It was observed that increase in the doping concentration of the emitter does not necessarily enhance the energy transfer in the near field. The energy-streamline method was used to model the lateral shift of the energy pathway, which is the trace of the Poynting vectors in the vacuum gap. The analysis performed in this study may facilitate the understanding of near-field radiation for applications such as thermal management in nanoelectronics, energy conversion systems, and nanothermal manufacturing.

Near-Field Thermal Radiation Between Mie Resonance-Based Metamaterials

2012 ◽  
Author(s):  
Mathieu Francoeur ◽  
Soumyadipta Basu ◽  
Spencer J. Petersen
Keyword(s):  
Heat Transfer ◽  
Radiative Heat Transfer ◽  
Radiative Heat ◽  
Near Field ◽  
Radiative Properties ◽  
Surface Polariton ◽  
Conversion Technologies ◽  
First Time ◽  
Vacuum Gap ◽  
Sub Wavelength

Near-field radiative heat transfer between dielectric-based metamaterials separated by a sub-wavelength vacuum gap is analyzed. Metamaterials made of silicon carbide spherical inclusions within a dielectric host medium of potassium bromide are considered. We show for the first time that surface polariton mediated near-field radiative heat transfer in both TE and TM polarizations may occur between dielectric-based structures. The results presented in this work also demonstrate that it is possible to engineer materials with designer radiative properties, which is crucial in many emerging energy conversion technologies.

Thermal transport across a pair of thin silicon films with the presence of minute vacuum gap: effect of film thickness on thermal characteristics

2016 ◽  
Vol 94 (9) ◽  
pp. 933-944 ◽  
Author(s):  
Haider Ali ◽  
Bekir Sami Yilbas
Keyword(s):  
Heat Transfer ◽  
Film Thickness ◽  
Energy Transport ◽  
Near Field ◽  
Radiation Heat Transfer ◽  
Silicon Films ◽  
Radiation Heat ◽  
Field Radiation ◽  
Thin Silicon ◽  
Vacuum Gap

Energy transport across a pair of thin silicon films with the vacuum gap at the films interface is studied. The Boltzmann transport equation is incorporated in the analysis and the solution for the transient frequency-dependent phonon distribution across the films pair is presented. To assess the phonon characteristics, equivalent equilibrium temperature is introduced, which resembles the average energy of all phonons around a local point when they redistribute adiabatically to an equilibrium state. Because the gap size is comparable to the mean free path of silicon, a near-field radiation heat transfer is incorporated across the film edges at the interface. The frequency cutoff method is used at the interface of the films and the phonons jump across the gap resembling the ballistic phonon contribution to the energy transport is accommodated. The thermal conductivity data predicted are validated with the data obtained from the previous study. The effect of near-field radiation heat transfer on temperature increase at the edges of the film, across the gap interface, is not considerable as compared to that corresponding to phonons transmitted across the gap. Increasing the first film thickness increases temperature difference across the gap, which is more pronounced for large gap sizes.

Microscale Thermal Energy Transfer Between Thin Films with Vacuum Gap at Interface

2019 ◽  
Vol 44 (2) ◽  
pp. 123-142 ◽  
Author(s):  
Haider Ali ◽  
Bekir Sami Yilbas
Keyword(s):  
Thin Film ◽  
Heat Transfer ◽  
Thermal Conductivity ◽  
Energy Transfer ◽  
Radiative Heat ◽  
Near Field ◽  
Silicon Film ◽  
Phonon Transport ◽  
Ballistic Phonons ◽  
Vacuum Gap

Abstract Transfer of phonons through a silicon–diamond thin film pair with a nano-size gap at the interface is examined. The thin film pair is thermally disturbed by introducing 301 K at the silicon film left edge while keeping the other edges of the thin films at a low temperature (300 K). The radiative phonon transport equation is solved numerically to quantify the phonon intensity distribution in the combined films. The frequency dependent formulation of phonon transport is incorporated in the transient analysis. The thermal boundary resistance is adopted at the interface in the formulations. The near-field radiative heat transfer is also adopted at the gap interface, as the vacuum gap size falls within the Casimir limit. The predictions of thermal conductivity are validated through the thermocouple data. It is observed that predictions of thermal conductivity are in agreement with the experimental data. The ballistic phonons play a major role in energy transfer through the gap; their contribution is more significant than that of the near-field radiative heat transfer. Enlarging the size of the gap reduces the influence of the ballistic phonons on the energy transfer in the films. Increasing the silicon film thickness alters the energy transfer through the gap; in this case, the equivalent equilibrium temperature difference is increased at the interface.

Optimization of a near-field thermophotovoltaic system operating at low temperature and large vacuum gap

2018 ◽  
Vol 210 ◽  
pp. 35-43 ◽  
Author(s):  
Mikyung Lim ◽  
Jaeman Song ◽  
Jihoon Kim ◽  
Seung S. Lee ◽  
Ikjin Lee ◽  
...  
Keyword(s):  
Low Temperature ◽  
Near Field ◽  
Vacuum Gap ◽  
System Operating

Energy Streamlines in Near-Field Thermal Radiation

2008 ◽  
Author(s):  
B. J. Lee ◽  
Z. M. Zhang
Keyword(s):  
Thermal Radiation ◽  
Near Field ◽  
Propagation Direction ◽  
Radiative Energy ◽  
Spectral Energy ◽  
Energy Propagation ◽  
Surface Polaritons ◽  
Poynting Vectors ◽  
Vacuum Gap ◽  
Effect Of Surface

In the present paper, we investigate the energy propagation direction in near-field thermal radiation between two semi-infinite surfaces separated by a vacuum gap. Based on the fluctuational electrodynamics, we demonstrate in detail that Poynting vectors for each parallel wavevector component (β) are decoupled due to the randomness of thermal radiation. The results reveal that the spectral radiative energy is transferred in infinite directions. By separately tracing the Poynting vector for each given β, the energy propagation direction in the vacuum gap is visualized. Depending on β values, there exist considerable lateral shifts of the energy streamline. The range of β values dominantly contributing to the spectral energy flux is identified for different wavelengths. Furthermore, the effect of surface polaritons on the lateral shift is also discussed.

scholarly journals Hyperbolic metamaterial-based near-field thermophotovoltaic system for hundreds of nanometer vacuum gap

2016 ◽  
Vol 24 (6) ◽  
pp. A635 ◽  
Author(s):  
Seokmin Jin ◽  
Mikyung Lim ◽  
Seung S. Lee ◽  
Bong Jae Lee
Keyword(s):  
Near Field ◽  
Hyperbolic Metamaterial ◽  
Vacuum Gap

Near-Field Radiation Calculated With an Improved Dielectric Function Model for Doped Silicon

2009 ◽  
Vol 132 (2) ◽  
Author(s):  
S. Basu ◽  
B. J. Lee ◽  
Z. M. Zhang
Keyword(s):  
Dielectric Function ◽  
Local Density ◽  
Near Field ◽  
Silicon Surfaces ◽  
Function Model ◽  
Doped Silicon ◽  
Field Radiation ◽  
Heavily Doped ◽  
Poynting Vectors ◽  
Vacuum Gap

This paper describes a theoretical investigation of near-field radiative heat transfer between doped silicon surfaces separated by a vacuum gap. An improved dielectric function model for heavily doped silicon is employed. The effects of doping level, polarization, and vacuum gap width on the spectral and total radiative transfer are studied based on the fluctuational electrodynamics. It is observed that increasing the doping concentration does not necessarily enhance the energy transfer in the near-field. The energy streamline method is used to model the lateral shift of the energy pathway, which is the trace of the Poynting vectors in the vacuum gap. The local density of states near the emitter is calculated with and without the receiver. The results from this study can help improve the understanding of near-field radiation for applications such as thermophotovoltaic energy conversion, nanoscale thermal imaging, and nanothermal manufacturing.

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