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.

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.

Modeling of Near-Field Concentrated Solar Thermophotovoltaic Microsystem

2014 ◽  
Author(s):  
Mahmoud Elzouka ◽  
Mukesh Kulsreshath ◽  
Sidy Ndao
Keyword(s):  
Power Density ◽  
Output Power ◽  
Conversion Efficiency ◽  
Near Field ◽  
Separation Distance ◽  
Heat Radiation ◽  
Cooling Power ◽  
Emitter Temperature ◽  
Pv Cell ◽  
Field Radiation

Modeling of a near-field concentrated solar thermophotovoltaic (STPV) microsystem is carried out to investigate the use of STPV-based solid-state energy conversion as a high power density MEMS power generator. Near-field radiation can be realized between two closely separated surfaces (i.e. order of radiation wavelength), resulting in the enhancement of the heat radiation flux orders of magnitudes higher than the blackbody limit, consequently increasing cell output power density. The Near-field STPV model consists of an absorber/emitter model used to estimate the net power absorbed from solar irradiance, a near-field radiation transfer model to evaluate the power tunneled from the emitter to the PV cell at different separation distances, and a PV cell model to determine the photocurrent generated due to thermal radiation absorbed. Results reveal that decreasing separation distance between the emitter and the PV cell increases the absorber/emitter thermal efficiency, increases conversion efficiency, and the power density (×100 far-field). The results also predict increase in cooling power requirement as the separation distance is decreased, which may be a limiting design parameter for near-field STPV microsystems. Based on the model, an overall conversion efficiency of 17% at a separation distance of 10 nm and emitter temperature of 2000 K with solar concentration 6000 sun can be reached; this corresponds to an output power density of 9×105 W/m2.

scholarly journals Accurate near-field calculation in the rigorous coupled-wave analysis method

2015 ◽  
Vol 17 (12) ◽  
pp. 125612 ◽  
Author(s):  
Martin Weismann ◽  
Dominic F G Gallagher ◽  
Nicolae C Panoiu
Keyword(s):  
Near Field ◽  
Field Calculation ◽  
Analysis Method ◽  
Wave Analysis ◽  
Rigorous Coupled Wave Analysis ◽  
Rigorous Coupled Wave ◽  
Coupled Wave

scholarly journals Extraordinary Optical Transmission by Hybrid Phonon–Plasmon Polaritons Using hBN Embedded in Plasmonic Nanoslits

Nanomaterials ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 1567
Author(s):  
Shinpei Ogawa ◽  
Shoichiro Fukushima ◽  
Masaaki Shimatani
Keyword(s):  
Optical Transmission ◽  
Hexagonal Boron Nitride ◽  
Incident Angle ◽  
Optical Filters ◽  
Extraordinary Optical Transmission ◽  
Light Manipulation ◽  
Rigorous Coupled Wave Analysis ◽  
Fabry Perot ◽  
Hyperbolic Dispersion ◽  
Rigorous Coupled Wave

Hexagonal boron nitride (hBN) exhibits natural hyperbolic dispersion in the infrared (IR) wavelength spectrum. In particular, the hybridization of its hyperbolic phonon polaritons (HPPs) and surface plasmon resonances (SPRs) induced by metallic nanostructures is expected to serve as a new platform for novel light manipulation. In this study, the transmission properties of embedded hBN in metallic one-dimensional (1D) nanoslits were theoretically investigated using a rigorous coupled wave analysis method. Extraordinary optical transmission (EOT) was observed in the type-II Reststrahlen band, which was attributed to the hybridization of HPPs in hBN and SPRs in 1D nanoslits. The calculated electric field distributions indicated that the unique Fabry–Pérot-like resonance was induced by the hybridization of HPPs and SPRs in an embedded hBN cavity. The trajectory of the confined light was a zigzag owing to the hyperbolicity of hBN, and its resonance number depended primarily on the aspect ratio of the 1D nanoslit. Such an EOT is also independent of the slit width and incident angle of light. These findings can not only assist in the development of improved strategies for the extreme confinement of IR light but may also be applied to ultrathin optical filters, advanced photodetectors, and optical devices.

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.

Sign in / Sign up

Export Citation Format

Share Document