NEW RESULTS ON OPTICAL ABSORPTION IN AMORPHOUS CADMIUM OXIDE FOR THE VISIBLE RANGE: A THEORETICAL APPROACH

Optical absorption of amorphous cadmium oxide in the visible region is investigated by considering the band-gap shift experienced by this material. At the same time, influence of oxygen partial pressure is studied so that new results related to absorption in the visible margin are obtained; these results agree well with experimental data. In addition, phonon density of states and its shift due to the band-gap shift are evaluated.

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Moments of phonon density of states spectra and characteristic phonon temperatures of wide band gap materials

physica status solidi (b) ◽

10.1002/pssb.200642284 ◽

2006 ◽

Vol 243 (12) ◽

pp. 2719-2727 ◽

Cited By ~ 9

Author(s):

Roland Pässler

Keyword(s):

Band Gap ◽

Density Of States ◽

Wide Band ◽

Phonon Density ◽

Phonon Density Of States ◽

Wide Band Gap

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Theoretical analysis on the sensitivity to partial pressure of oxygen of the band gap shift in CdO thin films

Modern Physics Letters B ◽

10.1142/s0217984916503711 ◽

2016 ◽

Vol 30 (31) ◽

pp. 1650371 ◽

Cited By ~ 1

Author(s):

M. A. Grado-Caffaro ◽

M. Grado-Caffaro

Keyword(s):

Thin Films ◽

Partial Pressure ◽

Band Gap ◽

Cadmium Oxide ◽

Visible Region ◽

Visible Range ◽

Partial Pressure Of Oxygen ◽

Sensitivity Functions ◽

Suitable Parameter ◽

Cdo Thin Films

With the aim of providing an analytical approach (not accurate numerical results), for the first time, the sensitivity to the partial pressure of oxygen of the shift in the energy band gap experienced by cadmium-oxide thin films is evaluated for the visible region by introducing a suitable parameter. The sensitivity to the above pressure of the spatial carrier density is determined and compared with the sensitivity relative to the band gap shift. The gradient of the CdO carrier concentration as a function of the partial pressure of oxygen appears in the expressions for the two above sensitivity functions but the goal of this paper is not computing numerically this gradient so only qualitative estimations are done. In relation to the above results, the kinetics relative to the formation of CdO thin films are investigated. In addition, the sensitivity to the pressure in question of the corresponding optical-absorption shift in the visible range is calculated.

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MAXIMUM DYNAMICAL DISORDER IN AMORPHOUS GaAs

Modern Physics Letters B ◽

10.1142/s0217984994000182 ◽

1994 ◽

Vol 08 (03) ◽

pp. 169-172 ◽

Cited By ~ 4

Author(s):

M.A. GRADO CAFFARO ◽

M. GRADO CAFFARO

Keyword(s):

Optical Absorption ◽

Absorption Coefficient ◽

Density Of States ◽

Far Infrared ◽

Conduction Band Edge ◽

Infrared Range ◽

Phonon Density ◽

Phonon Density Of States ◽

Low Frequencies ◽

Dynamical Disorder

Maximum dynamical disorder in amorphous gallium arsenide is investigated in a special way. In particular, this maximum disorder refers to distance and it is investigated in the context of optical absorption at very low frequencies in the far-infrared range when the photon energy is larger than 2Ec, Ec being the energy at the conduction band edge. Absorption coefficient is calculated and compared with experimental work. Phonon density of states is also evaluated.

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ON OPTICAL ABSORPTION OF AMORPHOUS CADMIUM OXIDE IN THE VISIBLE REGION

Modern Physics Letters B ◽

10.1142/s021798490200424x ◽

2002 ◽

Vol 16 (20) ◽

pp. 747-749 ◽

Cited By ~ 5

Author(s):

M. A. GRADO-CAFFARO ◽

M. GRADO-CAFFARO

Keyword(s):

Optical Absorption ◽

Oxygen Partial Pressure ◽

Partial Pressure ◽

Band Gap ◽

Cadmium Oxide ◽

Visible Region

Optical absorption of amorphous cadmium oxide in the visible region is discussed by considering the band-gap shift in the light of the Burstein–Moss model. Moreover, the influence of oxygen partial pressure is discussed.

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The Phonon Density of States of Solids from the Experimental Heat Capacity

Siberian Journal of Physics ◽

10.54362/1818-7919-2012-7-3-102-113 ◽

2012 ◽

Vol 7 (3) ◽

pp. 102-113

Author(s):

Viktor Naumov ◽

Alimbek Tagaev ◽

Anatoliy Musikhin

Keyword(s):

Experimental Data ◽

Heat Capacity ◽

Temperature Interval ◽

Density Of States ◽

Iteration Process ◽

Phonon Density ◽

Phonon Density Of States ◽

Experimental Heat ◽

The Difference ◽

The Right

The new method of determining the spectrum phonon density of states g(ω) from the experimental data in the heat capacity C(T), obtained in the wide temperature interval is suggested. At the primary stage g(ω) is described in symptomless ones (near zero and limit frequencies). The parameters can be determined from the C(T) curve. So the obtained zero coming for the phonon density of states g(ω) is made by the iteration process when the redistribution in the frequencies of the vibrating modes of the zero coming is done. The iteration process is connected with the difference reduction in the made and experimental heat capacity and managed by the redistribution of the vibrating modes. The method is viewed for the number of the model spectra with different degree of complication. The obtained results show the possibility of the singling out three peaks in g(ω) with the right description of their form. The phonon density of states for aluminum is determined and the comparison with the investigation results represented in the list of literature is done

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A Brief Study to Clarify Some Aspects Related to Vibrational Density of States for the Far Infrared Range in Amorphous Semiconductors

Active and Passive Electronic Components ◽

10.1155/1998/93964 ◽

1998 ◽

Vol 20 (3) ◽

pp. 143-145 ◽

Cited By ~ 1

Author(s):

M. A. Grado-Caffaro ◽

M. Grado-Caffaro

Keyword(s):

Optical Absorption ◽

Density Of States ◽

Far Infrared ◽

Structural Disorder ◽

Amorphous Semiconductors ◽

Infrared Range ◽

Phonon Density ◽

Phonon Density Of States ◽

Vibrational Density Of States ◽

Vibrational Density

Phonon density of states of amorphous semiconductors for the far-infrared range is examined analytically. On the basis of this formulation, optical absorption corresponding to structural disorder is evaluated and discussed at the far-infrared range for a-Ge and a-Si.

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Application of Diffuse Mismatch Theory to the Prediction of Thermal Boundary Resistance in Thin-Film High-Tc Superconductors

Journal of Heat Transfer ◽

10.1115/1.2830060 ◽

1998 ◽

Vol 120 (1) ◽

pp. 37-43 ◽

Cited By ~ 56

Author(s):

P. E. Phelan

Keyword(s):

Thin Film ◽

Experimental Data ◽

Density Of States ◽

Superconducting Devices ◽

Debye Model ◽

Boundary Resistance ◽

Thermal Boundary Resistance ◽

Phonon Density ◽

Phonon Density Of States ◽

And Performance

Thermal boundary resistance (Rb) plays an important role in the design and performance of thin-film high-temperature superconducting devices, such as infrared detectors and optical switches, which rely upon the temperature rise of the film as the basis for their operation. Although there is general agreement on the magnitude of Rb from experimental data, there is at present no generally accepted theory capable of predicting Rb for these films, particularly at the intermediate cryogenic temperatures where they are likely to be used. Here, the Diffuse Mismatch Model (DMM), which considers that all phonons reaching the interface between the film and substrate scatter diffusely, is applied to the calculation of Rb. The results indicate that when employing the Debye model for the phonon density of states, the DMM yields results slightly more in agreement with data than the Acoustic Mismatch Model (AMM). Considering the measured phonon density of states, however, greatly increases Rb over that calculated assuming the Debye model, thus bringing the DMM results in relatively good agreement with the experimental data.

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