scholarly journals A Computational Simulation of Using Tungsten Gratings in Near-Field Thermophotovoltaic Devices

2017 ◽  
Vol 139 (5) ◽  
Author(s):  
J. I. Watjen ◽  
X. L. Liu ◽  
B. Zhao ◽  
Z. M. Zhang
Keyword(s):  
Thermal Radiation ◽  
Band Gap ◽  
Alternative Energy ◽  
Near Field ◽  
Computational Simulation ◽  
Radiation Energy ◽  
Energy Conversion Efficiency ◽  
Pv Cell ◽  
Energy Harvesting System ◽  
Rigorous Coupled Wave

Near-field thermophotovoltaic (NFTPV) devices have received much attention lately as an alternative energy harvesting system, whereby a heated emitter exchanges super-Planckian thermal radiation with a photovoltaic (PV) cell to generate electricity. This work describes the use of a grating structure to enhance the power throughput of NFTPV devices, while increasing the energy conversion efficiency by ensuring that a large portion of the radiation entering the PV cell is above the band gap. The device contains a high-temperature tungsten grating that radiates photons to a room-temperature In0.18Ga0.82Sb PV cell through a vacuum gap of several tens of nanometers. Scattering theory is used along with the rigorous coupled-wave analysis (RCWA) to calculate the radiation energy exchange between the grating emitter and the TPV cell. A parametric study is performed by varying the grating depth, period, and ridge width in the range that can be fabricated using available fabrication technologies. It is found that the power output can be increased by 40% while improving the efficiency from 29.9% to 32.0% with a selected grating emitter as compared to the case of a flat tungsten emitter. Reasons for the enhancement are found to be due to the enhanced energy transmission coefficient close to the band gap. This work shows a possible way of improving NFTPV and sheds light on how grating structures interact with thermal radiation at the nanoscale.

scholarly journals A Computational Simulation of Using Tungsten Gratings in Near-Field Thermophotovoltaic Devices

2016 ◽  
Author(s):  
J. I. Watjen ◽  
X. L. Liu ◽  
B. Zhao ◽  
Z. M. Zhang
Keyword(s):  
Near Field ◽  
Computational Simulation ◽  
Radiation Exchange ◽  
Rigorous Coupled Wave Analysis ◽  
Pv Cell ◽  
Harvesting Systems ◽  
Field Radiation ◽  
Ridge Width ◽  
Thermal Emitter ◽  
Rigorous Coupled Wave

Near-field thermophotovoltaic (NFTPV) devices have received much attention lately as attractive energy harvesting systems, whereby a heated thermal emitter exchanges super-Planckian near-field radiation with a photovoltaic (PV) cell to generate electricity. This work describes the use of a grating structure to enhance the power throughput of NFTPV devices, while increasing thermal efficiency by ensuring that a large portion of the radiation entering the PV cell is above the bandgap. The device is modeled as a one-dimensional high-temperature tungsten grating on a tungsten substrate that radiates photons to a room-temperature In0.18Ga0.82Sb PV cell through a vacuum gap of several tens of nanometers. Scattering theory is used along with the rigorous coupled-wave analysis to calculate the radiation exchange between the grating emitter and the PV cell. A parametric study is performed by varying the grating depth, period, and ridge width in the range that can be fabricated using available fabrication technologies. By optimizing the grating parameters, it is found that the power output can be improved by 40% while increasing the energy efficiency by 6% as compared with the case of a flat tungsten emitter. Reasons for the enhancement are investigated and found to be due to the surface plasmon polariton resonance, which shifts towards lower frequencies. This work shows a possible way of improving NFTPV and sheds light on how grating structures interact with thermal radiation at the nanoscale.

A Solar Thermophotovoltaic System Using Spectrally Controlled Monolithic Planar Thermal Emitter/Absorber

2016 ◽  
Author(s):  
Hiroo Yugami ◽  
Asaka Kohiyama ◽  
Makoto Shimizu ◽  
Fumitada Iguchi
Keyword(s):  
Thermal Radiation ◽  
High Efficiency ◽  
Radiation Spectrum ◽  
Spectral Response ◽  
Storage System ◽  
Radiation Energy ◽  
System Efficiency ◽  
Lower Efficiency ◽  
Pv Cell ◽  
Thermal Emitter

Solar-thermophotovoltaic system is expected to have high efficiency by converting wide spectral range solar energy into useful thermal radiation energy. However, the experimental STPV system shows much lower efficiency than theoretical one. To achieve high-efficiency, it is essential to obtain good spectrally matching between thermal radiation spectrum and PV cells spectral response. In this paper, the power generation tests using the whole configuration of the STPV system is described. The conversion efficiency of GaSb PV cell is estimated to be 20 to 23% against to the light intensity irradiated on the PV cell surface. The net system efficiency of 1.9% can be achieved. The application of thermal storage system to the STPV is also considered.

scholarly journals Near-field thermophotovoltaics for efficient heat to electricity conversion at high power density

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Rohith Mittapally ◽  
Byungjun Lee ◽  
Linxiao Zhu ◽  
Amin Reihani ◽  
Ju Won Lim ◽  
...  
Keyword(s):  
Power Density ◽  
High Power ◽  
High Efficiency ◽  
Near Field ◽  
Electrical Power ◽  
Photovoltaic Cells ◽  
High Power Density ◽  
Pv Cell ◽  
Electrical Power Output ◽  
Power Densities

AbstractThermophotovoltaic approaches that take advantage of near-field evanescent modes are being actively explored due to their potential for high-power density and high-efficiency energy conversion. However, progress towards functional near-field thermophotovoltaic devices has been limited by challenges in creating thermally robust planar emitters and photovoltaic cells designed for near-field thermal radiation. Here, we demonstrate record power densities of ~5 kW/m2 at an efficiency of 6.8%, where the efficiency of the system is defined as the ratio of the electrical power output of the PV cell to the radiative heat transfer from the emitter to the PV cell. This was accomplished by developing novel emitter devices that can sustain temperatures as high as 1270 K and positioning them into the near-field (<100 nm) of custom-fabricated InGaAs-based thin film photovoltaic cells. In addition to demonstrating efficient heat-to-electricity conversion at high power density, we report the performance of thermophotovoltaic devices across a range of emitter temperatures (~800 K–1270 K) and gap sizes (70 nm–7 µm). The methods and insights achieved in this work represent a critical step towards understanding the fundamental principles of harvesting thermal energy in the near-field.

Near-field and far-field effects in thermal radiation from metallic carbon nanotubes

2007 ◽  
Author(s):  
Andrei M. Nemilentsau ◽  
Gregory Ya. Slepyan ◽  
Sergey A. Maksimenko
Keyword(s):  
Carbon Nanotubes ◽  
Thermal Radiation ◽  
Near Field ◽  
Far Field ◽  
Field Effects

Near-Field Thermal Radiation

2020 ◽  
pp. 741-776
Author(s):  
John R. Howell ◽  
M. Pinar Mengüç ◽  
Kyle Daun ◽  
Robert Siegel
Keyword(s):  
Thermal Radiation ◽  
Near Field
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