Near-infrared–to–visible highly selective thermal emitters based on an intrinsic semiconductor

Control of the thermal emission spectra of emitters will result in improved energy utilization efficiency in a broad range of fields, including lighting, energy harvesting, and sensing. In particular, it is challenging to realize a highly selective thermal emitter in the near-infrared–to–visible range, in which unwanted thermal emission spectral components at longer wavelengths are significantly suppressed, whereas strong emission in the near-infrared–to–visible range is retained. To achieve this, we propose an emitter based on interband transitions in a nanostructured intrinsic semiconductor. The electron thermal fluctuations are first limited to the higher-frequency side of the spectrum, above the semiconductor bandgap, and are then enhanced by the photonic resonance of the structure. Theoretical calculations indicate that optimized intrinsic Si rod-array emitters with a rod radius of 105 nm can convert 59% of the input power into emission of wavelengths shorter than 1100 nm at 1400 K. It is also theoretically indicated that emitters with a rod radius of 190 nm can convert 84% of the input power into emission of <1800-nm wavelength at 1400 K. Experimentally, we fabricated a Si rod-array emitter that exhibited a high peak emissivity of 0.77 at a wavelength of 790 nm and a very low background emissivity of <0.02 to 0.05 at 1100 to 7000 nm, under operation at 1273 K. Use of a nanostructured intrinsic semiconductor that can withstand high temperatures is promising for the development of highly efficient thermal emitters operating in the near-infrared–to–visible range.

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Facile Synthesis of GdF3:Yb3+, Er3+, Tm3+@TiO2–Ag Core–Shell Ellipsoids Photocatalysts for Photodegradation of Methyl Orange Under UV, Visible, and NIR Light Irradiation

Journal of Nanoscience and Nanotechnology ◽

10.1166/jnn.2018.16021 ◽

2018 ◽

Vol 18 (12) ◽

pp. 8216-8224 ◽

Cited By ~ 1

Author(s):

Yu Gao ◽

Xiaodong Ren ◽

Cheng Shi ◽

Guiyan Zhao ◽

Yanfeng Bi ◽

...

Keyword(s):

Methyl Orange ◽

Near Infrared ◽

High Surface ◽

High Surface Area ◽

Energy Utilization ◽

Utilization Efficiency ◽

Core Shell ◽

Broadband Absorption ◽

New Strategy ◽

Uv Visible

To enhance solar energy utilization efficiency, goal-directed design of architectures by combining nanocomponents of radically different properties, such as plasmonic, upconversion, and photocatalytic properties may provide a promising method to utilize the most energy in sunlight. In this work, a new strategy was adopted to fabricate a series of plasmonic Ag nanoparticles decorated GdF3:Yb3+, Er3+, Tm3+-core@porous-TiO2-shell ellipsoids, which exhibit high surface area, good stability, broadband absorption from ultraviolet to near infrared, and excellent photocatalytic activity. The results showed that photocatalytic activities of the as-obtained photocatalysts was higher than that of pure GdF3:Yb3+, Er3+, Tm3+ and GdF3:Yb3+, Er3+, Tm3+@TiO2 samples through the comparison of photodegradation rates of methyl orange under UV, visible, and NIR irradiation. The possible photocatalytic mechanism indicates that hydroxyl radicals and superoxide radical play a pivotal role in the photodegradation. Furthermore, the materials also showed exceptionally high stability and reusability under UV, visible, and NIR irradiation. All these results reveal that core–shell hierarchical ellipsoids exhibit great prospects for developing efficient solar photocatalysts.

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One-Photon Upconversion-Like Photolysis: A New Strategy to Achieve Long-Wavelength Light-Excitable Photolysis

Synlett ◽

10.1055/s-0040-1707100 ◽

2020 ◽

Vol 31 (12) ◽

pp. 1129-1134 ◽

Cited By ~ 2

Author(s):

Weiping Wang ◽

Wen Lv

Keyword(s):

Near Infrared ◽

Energy Utilization ◽

Utilization Efficiency ◽

Infrared Light ◽

Excitation Wavelength ◽

Long Wavelength ◽

New Strategy ◽

The One ◽

Biological And Medical Applications ◽

Wavelength Light

Photolysis reactions are widely utilized to release desired molecules under the control of light irradiation in the fields of photochemistry, biology, and drug delivery. In biological and medical applications, it is highly desired to increase the excitation wavelength for activating photolysis reactions, since the long-wavelength light (red or near-infrared light) has deep tissue penetration depth and low photocytotoxicity. Here, we briefly summarize current strategies of achieving long-wavelength light-excitable photolysis. We highlight our recently developed strategy of one-photon upconversion-like photolysis. Compared with the multiphoton upconversion-based photolysis, the one-photon strategy has a simpler energy transfer process and a higher energy utilization efficiency, providing a new path of activating photolysis reactions with increased excitation wavelength and photolysis quantum yield.

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Phase reddening on asteroid Bennu from visible and near-infrared spectroscopy

Astronomy and Astrophysics ◽

10.1051/0004-6361/202039552 ◽

2020 ◽

Vol 644 ◽

pp. A142 ◽

Cited By ~ 1

Author(s):

S. Fornasier ◽

P. H. Hasselmann ◽

J. D. P Deshapriya ◽

M. A. Barucci ◽

B. E. Clark ◽

...

Keyword(s):

Phase Angle ◽

Near Infrared ◽

Fine Particles ◽

Thermal Emission ◽

Global Scale ◽

Spectral Phase ◽

Visible Range ◽

Spectral Slope ◽

Sample Collection ◽

Multiple Wavelength

Context. The NASA mission OSIRIS-REx (Origins, Spectral Interpretation, Resource Identification, and Security–Regolith Explorer) has been observing near-Earth asteroid (101955) Bennu in close proximity since December 2018. In October 2020, the spacecraft collected a sample of surface material from Bennu to return to Earth. Aims. In this work, we investigate spectral phase reddening – that is, the variation of spectral slope with phase angle – on Bennu using spectra acquired by the OSIRIS-REx Visible and InfraRed Spectrometer (OVIRS) covering a phase angle range of 8–130°. We investigate this process at the global scale and for some localized regions of interest (ROIs), including boulders, craters, and the designated sample collection sites of the OSIRIS-REx mission. Methods. Spectra were wavelength- and flux-calibrated, then corrected for the out-of-band contribution and thermal emission, resampled, and finally converted into radiance factor per standard OVIRS processing. Spectral slopes were computed in multiple wavelength ranges from spectra normalized at 0.55 μm. Results. Bennu has a globally negative spectra slope, which is typical of B-type asteroids. The spectral slope gently increases in a linear way up to a phase angle of 90°, where it approaches zero. The spectral phase reddening is monotonic and wavelength-dependent with highest values in the visible range. Its coefficient is 0.00044 μm−1 deg−1 in the 0.55–2.5 μm range. For observations of Bennu acquired at high phase angle (130°), phase reddening increases exponentially, and the spectral slope becomes positive. Similar behavior was reported in the literature for the carbonaceous chondrite Mukundpura in spectra acquired at extreme geometries. Some ROIs, including the sample collection site, Nightingale, have a steeper phase reddening coefficient than the global average, potentially indicating a surface covered by fine material with high micro-roughness. Conclusions. The gentle spectral phase reddening effect on Bennu is similar to that observed in ground-based measurements of other B-type asteroids, but much lower than that observed for other low-albedo bodies such as Ceres or comet 67P/Churyumov-Gerasimenko. Monotonic reddening may be associated with the presence of fine particles at micron scales and/or of particles with fractal structure that introduce micro- and sub-micro roughness across the surface of Bennu.

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Regional integrated energy system schemes selection based on risk expectation and Mahalanobis-Taguchi system

Journal of Intelligent & Fuzzy Systems ◽

10.3233/jifs-190211 ◽

2021 ◽

pp. 1-18

Author(s):

Jiahang Yuan ◽

Yun Li ◽

Xinggang Luo ◽

Lingfei Li ◽

Zhongliang Zhang ◽

...

Keyword(s):

Energy Demand ◽

Choquet Integral ◽

Subjective Evaluation ◽

Risk Attitude ◽

Energy System ◽

Energy Utilization ◽

Utilization Efficiency ◽

Energy Structure ◽

Fuzzy Measures ◽

Integrated Energy System

Regional integrated energy system (RIES) provides a platform for coupling utilization of multi-energy and makes various energy demand from client possible. The suitable RIES composition scheme will upgrade energy structure and improve integrated energy utilization efficiency. Based on a RIES construction project in Jiangsu province, this paper proposes a new multi criteria decision-making (MCDM) method for the selection of RIES schemes. Because that subjective evaluation on RIES schemes benefit under criteria has uncertainty and hesitancy, intuitionistic trapezoidal fuzzy number (ITFN) which has the better capability to model ill-known quantities is presented. In consideration of risk attitude and interdependency of criteria, a new decision model with risk coefficients, Mahalanobis-Taguchi system and Choquet integral is proposed. Firstly, the decision matrices given by experts are normalized, and then are transformed to minimum expectation matrices according to different risk coefficients. Secondly, the weights of criteria from different experts are calculated by Mahalanobis-Taguchi system. Mobius transformation coefficients based on interaction degree are to calculate 2-order additive fuzzy measures, and then the comprehensive weights of criteria are obtained by fuzzy measures and Choquet integral. Thirdly, based on group decision consensus requirement, the weights of experts are obtained by the maximum entropy and grey correlation. Fourthly, the minimum expectation matrices are aggregated by the intuitionistic trapezoidal fuzzy Bonferroni mean operator. Thus, the ranking result according to the comparison rules using the minimum expectation and the maximum expectation is obtained. Finally, an illustrative example is taken in the present study to make the proposed method comprehensible.

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Coordination of Industrial Load Management and Micro-Turbines for Improving Renewable Energy Utilization Efficiency

2020 IEEE 4th Conference on Energy Internet and Energy System Integration (EI2) ◽

10.1109/ei250167.2020.9347373 ◽

2020 ◽

Author(s):

Bin Lin ◽

Kaiwen Zeng ◽

Haizhu Wang ◽

Jianing Liu ◽

Bin Du ◽

...

Keyword(s):

Renewable Energy ◽

Energy Utilization ◽

Utilization Efficiency ◽

Load Management

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Enhancing sub-bandgap external quantum efficiency by photomultiplication for narrowband organic near-infrared photodetectors

Nature Communications ◽

10.1038/s41467-021-24500-2 ◽

2021 ◽

Vol 12 (1) ◽

Author(s):

Jonas Kublitski ◽

Axel Fischer ◽

Shen Xing ◽

Lukasz Baisinger ◽

Eva Bittrich ◽

...

Keyword(s):

Charge Transfer ◽

Quantum Efficiency ◽

External Quantum Efficiency ◽

Near Infrared ◽

Optical Cavity ◽

Hole Injection ◽

Visible Range ◽

Absorption Region ◽

Electromagnetic Signals ◽

Organic Photodetectors

AbstractDetection of electromagnetic signals for applications such as health, product quality monitoring or astronomy requires highly responsive and wavelength selective devices. Photomultiplication-type organic photodetectors have been shown to achieve high quantum efficiencies mainly in the visible range. Much less research has been focused on realizing near-infrared narrowband devices. Here, we demonstrate fully vacuum-processed narrow- and broadband photomultiplication-type organic photodetectors. Devices are based on enhanced hole injection leading to a maximum external quantum efficiency of almost 2000% at −10 V for the broadband device. The photomultiplicative effect is also observed in the charge-transfer state absorption region. By making use of an optical cavity device architecture, we enhance the charge-transfer response and demonstrate a wavelength tunable narrowband photomultiplication-type organic photodetector with external quantum efficiencies superior to those of pin-devices. The presented concept can further improve the performance of photodetectors based on the absorption of charge-transfer states, which were so far limited by the low external quantum efficiency provided by these devices.

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Shoreline Changes along Northern Ibaraki Coast after the Great East Japan Earthquake of 2011

Remote Sensing ◽

10.3390/rs13071399 ◽

2021 ◽

Vol 13 (7) ◽

pp. 1399

Author(s):

Quang Nguyen Hao ◽

Satoshi Takewaka

Keyword(s):

Near Infrared ◽

Thermal Emission ◽

Sandy Beaches ◽

Great East Japan Earthquake ◽

Shoreline Changes ◽

Run Up ◽

Tsunami Run Up ◽

Sentinel 2 ◽

Infrared Radiometer

In this study, we analyze the influence of the Great East Japan Earthquake, which occurred on 11 March 2011, on the shoreline of the northern Ibaraki Coast. After the earthquake, the area experienced subsidence of approximately 0.4 m. Shoreline changes at eight sandy beaches along the coast are estimated using various satellite images, including the ASTER (Advanced Spaceborne Thermal Emission and Reflection Radiometer), ALOS AVNIR-2 (Advanced Land Observing Satellite, Advanced Visible and Near-infrared Radiometer type 2), and Sentinel-2 (a multispectral sensor). Before the earthquake (for the period March 2001–January 2011), even though fluctuations in the shoreline position were observed, shorelines were quite stable, with the averaged change rates in the range of ±1.5 m/year. The shoreline suddenly retreated due to the earthquake by 20–40 m. Generally, the amount of retreat shows a strong correlation with the amount of land subsidence caused by the earthquake, and a moderate correlation with tsunami run-up height. The ground started to uplift gradually after the sudden subsidence, and shoreline positions advanced accordingly. The recovery speed of the beaches varied from +2.6 m/year to +6.6 m/year, depending on the beach conditions.

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Evaluation of Energy Efficiency for a CCHP System With Available Microturbine

Volume 3: Turbo Expo 2007 ◽

10.1115/gt2007-27883 ◽

2007 ◽

Cited By ~ 2

Author(s):

H. X. Liang ◽

Q. W. Wang

Keyword(s):

Gas Turbine ◽

Waste Heat ◽

Energy System ◽

Primary Energy ◽

Economic Benefits ◽

Optimal Operation ◽

Energy Utilization ◽

Utilization Efficiency ◽

Energetic Efficiency ◽

Efficiency Evaluation

This paper deals with the problem of energy utilization efficiency evaluation of a microturbine system for Combined Cooling, Heating and Power production (CCHP). The CCHP system integrates power generation, cooling and heating, which is a type of total energy system on the basis of energy cascade utilization principle, and has a large potential of energy saving and economical efficiency. A typical CCHP system has several options to fulfill energy requirements of its application, the electrical energy can be produced by a gas turbine, the heat can be generated by the waste heat of a gas turbine, and the cooling load can be satisfied by an absorption chiller driven by the waste heat of a gas turbine. The energy problem of the CCHP system is so large and complex that the existing engineering cannot provide satisfactory solutions. The decisive values for energetic efficiency evaluation of such systems are the primary energy generation cost. In this paper, in order to reveal internal essence of CCHP, we have analyzed typical CCHP systems and compared them with individual systems. The optimal operation of this system is dependent upon load conditions to be satisfied. The results indicate that CCHP brings 38.7 percent decrease in energy consumption comparing with the individual systems. A CCHP system saves fuel resources and has the assurance of economic benefits. Moreover, two basic CCHP models are presented for determining the optimum energy combination for the CCHP system with 100kW microturbine, and the more practical performances of various units are introduced, then Primary Energy Ratio (PER) and exergy efficiency (α) of various types and sizes systems are analyzed. Through exergy comparison performed for two kinds of CCHP systems, we have identified the essential principle for high performance of the CCHP system, and consequently pointed out the promising features for further development.

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