One-dimensional narrow-band conductors

2021 ◽  
Vol 47 (9) ◽  
pp. 715-739
Author(s):  
L. A. Pastur ◽  
V. V. Slavin ◽  
A. A. Krivchikov
Keyword(s):  
Narrow Band ◽  
One Dimensional

Full-Spectrum k-Distribution Model for Radiation in Gas Based on Multi-Group Methods

2014 ◽  
Vol 1008-1009 ◽  
pp. 839-845
Author(s):  
Yue Zhou ◽  
Qiang Wang ◽  
Hai Yang Hu
Keyword(s):  
Narrow Band ◽  
Wide Band ◽  
Distribution Model ◽  
Full Spectrum ◽  
Distribution Method ◽  
One Dimensional ◽  
Group Methods ◽  
Monotonically Increasing Function ◽  
Homogeneous Media ◽  
Increasing Function

The k-distribution method applied in narrow band and wide band is extended to the full spectrum based on spectroscopic datebase HITEMP, educing the full-spectrum k-distribution model. Absorption coefficents in this model are reordered into a smooth,monotonically increasing function such that the intensity calculations are performed only once for each absorption coefficent value and the resulting computations are immensely more efficent.Accuracy of this model is examined for cases ranging from homogeneous one-dimensional carbon dioxide to inhomogeneous ones with simultaneous variations in temperature. Comparision with line-by-line calculations (LBL) and narrow-band k-distribution (NBK) method as well as wide-band k-distribution (WBK) method shows that the full-spectrum k-distribution model is exact for homogeneous media, although the errors are greater than the other two models. After dividing the absorption coefficients into several groups according to their temperature dependence, the full-spectrum k-distribution model achieves line-by-line accuracy for gases inhomogeneous in temperature, accompanied by lower computational expense as compared to NBK model or WBK model. It is worth noting that a new grouping scheme is provided in this paper.

scholarly journals Phosphonate Metal-Organic Frameworks: A Novel Family of Semiconductors

2020 ◽  
Author(s):  
Konrad Siemensmeyer ◽  
Craig A. Peeples ◽  
Patrik Tholen ◽  
Bünyemin Çoşut ◽  
Gabriel Hanna ◽  
...  
Keyword(s):  
Solid State ◽  
Dft Calculations ◽  
Band Gap ◽  
Narrow Band ◽  
Metal Organic Framework ◽  
Metal Organic Frameworks ◽  
One Dimensional ◽  
Metal Organic ◽  
Copper Dimers ◽  
Electrodes For Supercapacitors

<p>Herein is reported the first semiconducting and magnetic phosphonate metal-organic framework (MOF), TUB75, which contains a one-dimensional inorganic building unit composed of a zig-zag chain of corner-sharing copper dimers. The solid-state UV-Vis spectrum of TUB75 reveals the existence of a narrow band gap of 1.4 eV, which agrees well with the 1.77 eV one obtained from DFT calculations. Magnetization measurements show that TUB75 is composed of antiferromagnetically coupled copper dimer chains. Due to their rich structural chemistry and exceptionally high thermal/chemical stabilities, phosphonate MOFs like TUB75 may open new vistas in engineerable electrodes for supercapacitors. </p>

scholarly journals Photonic Crystals with a Defect Fabricated by Two-Photon Polymerization for the Infrared Spectral Range

Optics ◽  
2021 ◽  
Vol 2 (4) ◽  
pp. 284-291
Author(s):  
Victoria Paige Stinson ◽  
Serang Park ◽  
Micheal McLamb ◽  
Glenn Boreman ◽  
Tino Hofmann
Keyword(s):  
Photonic Crystal ◽  
Photonic Crystals ◽  
Narrow Band ◽  
Defect Mode ◽  
Defect Modes ◽  
One Dimensional ◽  
Two Photon ◽  
Infrared Spectral Range ◽  
Infrared Spectral ◽  
Good Agreement

One-dimensional photonic crystals composed of alternating layers with high- and low-density were fabricated using two-photon polymerization from a single photosensitive polymer for the infrared spectral range. By introducing single high-density layers to break the periodicity of the photonic crystals, a narrow-band defect mode is induced. The defect mode is located in the center of the photonic bandgap of the one-dimensional photonic crystal. The fabricated photonic crystals were investigated using infrared reflection measurements. Stratified-layer optical models were employed in the design and characterization of the spectral response of the photonic crystals. A very good agreement was found between the model-calculated and measured reflection spectra. The geometric parameters of the photonic crystals obtained as a result of the optical model analysis were found to be in good agreement with the nominal dimensions of the photonic crystal constituents. This is supported by complimentary scanning electron microscope imaging, which verified the model-calculated, nominal layer thicknesses. Conventionally, the accurate fabrication of such structures would require layer-independent print parameters, which are difficult to obtain with high precision. In this study an alternative approach is employed, using density-dependent scaling factors, introduced here for the first time. Using these scaling factors a fast and true-to-design method for the fabrication of layers with significantly different surface-to-volume ratios. The reported observations furthermore demonstrate that the location and amplitude of defect modes is extremely sensitive to any layer thickness non-uniformities in the photonic crystal structure. Considering these capabilities, one-dimensional photonic crystals engineered with defect modes can be employed as narrow band filters, for instance, while also providing a method to quantify important fabrication parameters.

Sign in / Sign up

Export Citation Format

Share Document