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.

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.

Investigation of Reoxidation and Phosphorus Behavior in HF-Treated Heavily Doped Silicon Surfaces

1993 ◽  
Vol 32 (Part 1, No. 11A) ◽  
pp. 4863-4869 ◽  
Author(s):  
Yoshitomo Kamiura ◽  
Yusuke Mizokawa ◽  
Makio Iida ◽  
Yoshihiko Isobe ◽  
Kazunori Kawamoto
Keyword(s):  
Silicon Surfaces ◽  
Doped Silicon ◽  
Heavily Doped

Tuning near field radiation by doped silicon

2013 ◽  
Vol 102 (18) ◽  
pp. 183114 ◽  
Author(s):  
Jiawei Shi ◽  
Pengfei Li ◽  
Baoan Liu ◽  
Sheng Shen
Keyword(s):  
Near Field ◽  
Doped Silicon ◽  
Field Radiation

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.

Tuning Near Field Radiation by Doped Silicon

2013 ◽  
Author(s):  
Jiawei Shi ◽  
Sheng Shen
Keyword(s):  
Silicon Dioxide ◽  
Theoretical Calculation ◽  
Carrier Concentration ◽  
Tuning Range ◽  
Near Field ◽  
Bulk Silicon ◽  
Doped Silicon ◽  
Theoretical Predictions ◽  
Field Radiation ◽  
Radiation Measurements

In this letter, we demonstrate theoretically and experimentally that bulk silicon can be employed to overcome the challenge of tuning near field radiation. Theoretical calculation shows that the nanoscale radiation between bulk silicon and silicon dioxide can be tuned by changing the carrier concentration of silicon. Near field radiation measurements are carried out on multiple bulk silicon samples with different doping concentrations. The measured near field conductance agrees well with theoretical predictions, which demonstrates a tuning range from 2 nW/K to 6 nW/K at a gap of ∼60 nm.

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.

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