A new model for the absorption coefficient of narrow‐gap (Hg,Cd)Te that simultaneously considers band tails and band filling

ABSTRACTOptical non-linearity of cobalt oxide with SiO2-TiO2 additives was investigated, and the change mechanism of the refractive index (n) and extinction coefficient (k), based on the relation between band structure and optical non-linearity of the thin films, was discussed. Refractive index and extinction coefficient of Co3O4 thin films in the ground state were 3.17 and 0.42, respectively. Both n and k decreased by irradiation from a pulse laser with 650 nm of wavelength (1.91eV). These values in the excited state were 2.91 and 0.41, respectively. n2 estimated from the change of n and k was −2.8 ×10−11 m2/W. The film had a band gap corresponding to 2.06eV, indicating that it was widened by the band filling effect during the laser irradiation at 1.91eV, and this led to the decrease in absorption coefficient and refractive index.

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Optical Absorption In Hg1−xCdxTe

MRS Proceedings ◽

10.1557/proc-484-667 ◽

1997 ◽

Vol 484 ◽

Author(s):

Vaidya Nathan

Keyword(s):

Experimental Data ◽

Optical Absorption ◽

Band Structure ◽

Absorption Coefficient ◽

Numerical Results ◽

Recent Experimental Data ◽

Narrow Gap ◽

Interband Transitions ◽

Linear Absorption Coefficient ◽

Linear Absorption

AbstractThe theory of optical absorption due to interband transitions in direct-gap semiconductors is revisited. A new analytical expression for linear absorption coefficient in narrow-gap semiconductors is obtained by including the nonparabolic band structure due to Keldysh and Burstein-Moss shift. Numerical results are obtained for Hg1−xCdxTe for several values of x and temperature, and compared with recent experimental data. The agreement is found to be good.

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Magneto-optical anisotropy in the absorption coefficient of narrow-gap quantum wells

Physica B Condensed Matter ◽

10.1016/s0921-4526(99)03054-9 ◽

2000 ◽

Vol 284-288 ◽

pp. 1928-1929 ◽

Cited By ~ 1

Author(s):

V. López-Richard ◽

G.E. Marques ◽

C. Trallero-Giner

Keyword(s):

Absorption Coefficient ◽

Quantum Wells ◽

Optical Anisotropy ◽

Narrow Gap

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A Novel Theoretical Modeling for Predicting the Sound Absorption of Woven Fabrics Using Modification of Sound Wave Equation and Genetic Algorithm

Autex Research Journal ◽

10.2478/aut-2020-0060 ◽

2021 ◽

Vol 0 (0) ◽

Author(s):

Valentinus Galih Vidia Putra ◽

Irwan ◽

Andrian Wijayono ◽

JulianyNingsih Mohamad ◽

Yusril Yusuf

Keyword(s):

Genetic Algorithms ◽

Wave Equation ◽

Absorption Coefficient ◽

Sound Wave ◽

Sound Absorption ◽

Wave Equations ◽

Woven Fabrics ◽

Woven Fabric ◽

Sound Absorption Coefficient ◽

New Model

Abstract Woven fabric in Indonesia is generally known as a material for making clothes and it has been applied as an interior finishing material in buildings, such as sound absorbent material. This study presents a new method for predicting the sound absorption of woven fabrics using a modification of the wave equations and using genetic algorithms. The main aim of this research is to study the sound absorption properties of woven fabric by modeling using a modification of the sound wave equations and using genetic algorithms. A new model for predicting the sound absorption coefficient of woven fabric (plain, twill 2/1, rips and satin fabric) as a function of porosity, the weight of the fabric, the thickness of the fabric, and frequency of the sound wave, was determined in this paper. In this research, the sound absorption coefficient equation was obtained using the modification of the sound wave equation as well as using genetic algorithms. This new model included the influence of the sound absorption coefficient phenomenon caused by porosity, the weight of the fabric, the thickness of fabric as well as the frequency of the sound wave. In this study, experimental data showed a good agreement with the model

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A new model for statistical error analysis in XAS: about the distribution function of the absorption coefficient

Journal of Synchrotron Radiation ◽

10.1107/s0909049500015326 ◽

2001 ◽

Vol 8 (2) ◽

pp. 264-266 ◽

Cited By ~ 2

Author(s):

Emmanuel Curis ◽

Simone Bénazeth

Keyword(s):

Distribution Function ◽

Error Analysis ◽

Absorption Coefficient ◽

Statistical Error ◽

New Model

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Impact of Semiconductor Band Tails and Band Filling on Photovoltaic Efficiency Limits

ACS Energy Letters ◽

10.1021/acsenergylett.0c02362 ◽

2020 ◽

pp. 52-57

Author(s):

Joeson Wong ◽

Stefan T. Omelchenko ◽

Harry A. Atwater

Keyword(s):

Photovoltaic Efficiency ◽

Band Filling ◽

Band Tails

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The Hitachi Model HS-8 Electron Microscope

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100061203 ◽

1967 ◽

Vol 25 ◽

pp. 238-239

Author(s):

H. Akabori ◽

K. Nishiwaki ◽

K. Yoneta

Keyword(s):

Electron Microscope ◽

New Model ◽

Predecessor Model

By improving the predecessor Model HS- 7 electron microscope for the purpose of easier operation, we have recently completed new Model HS-8 electron microscope featuring higher performance and ease of operation.

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Is there a “universal” MAC equation?

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100134740 ◽

1990 ◽

Vol 48 (2) ◽

pp. 228-229

Author(s):

Robert E. Ogilvie

Keyword(s):

Absorption Coefficient ◽

Atomic Absorption ◽

Atomic Number ◽

X Ray ◽

Time Period ◽

Image Position

The search for an empirical absorption equation begins with the work of Siegbahn (1) in 1914. At that time Siegbahn showed that the value of (μ/ρ) for a given element could be expressed as a function of the wavelength (λ) of the x-ray photon by the following equationwhere C is a constant for a given material, which will have sudden jumps in value at critial absorption limits. Siegbahn found that n varied from 2.66 to 2.71 for various solids, and from 2.66 to 2.94 for various gases.Bragg and Pierce (2) , at this same time period, showed that their results on materials ranging from Al(13) to Au(79) could be represented by the followingwhere μa is the atomic absorption coefficient, Z the atomic number. Today equation (2) is known as the “Bragg-Pierce” Law. The exponent of 5/2(n) was questioned by many investigators, and that n should be closer to 3. The work of Wingardh (3) showed that the exponent of Z should be much lower, p = 2.95, however, this is much lower than that found by most investigators.

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