scholarly journals Estudo das propriedades ópticas em pontos quânticos de CdTe carregados

2020 ◽  
Vol 41 (2) ◽  
pp. 205
Author(s):  
Silvio José Prado
Keyword(s):  
Optical Properties ◽  
Absorption Spectrum ◽  
Optical Absorption ◽  
Quantum Dot ◽  
Absorption Coefficient ◽  
Optical Absorption Spectrum ◽  
Incident Light ◽  
Charge Carriers ◽  
The Right ◽  
Cdte Quantum Dot

In this article we theoretically study how the presence of charge carriers added to the conduction and valence band of a spherical CdTe quantum dot affects the optical properties, especially the absorption coefficient. For this study, we simulated the interband optical absorption spectrum for incident light with circular polarizations on the left (ê-), on the right (ê+) and linear (êz). We also consider Coulomb's interaction between optically excited and added carriers.

Effective Dielectric Function of Porous Silicon: the Transverse Component

1994 ◽  
Vol 358 ◽  
Author(s):  
G. Gumbs
Keyword(s):  
Absorption Spectrum ◽  
Absorption Coefficient ◽  
Electron Density ◽  
Quantum Wires ◽  
Interband Transition ◽  
Incident Light ◽  
Transverse Component ◽  
Effect Of Temperature ◽  
High Electron ◽  
Confining Potential

ABSTRACTA self-consistent many-body theory is developed to study the effect of temperature and electron density on the interband absorption coefficient and the frequency-dependent refractive index for an array of isolated quantum wires. The peaks in the absorption coefficient correspond to interband transitions resulting in the resonant absorption of light. The oscillations in the derivative spectrum are due to the quantization of the energy levels related to the in-plane confining potential for such reduced dimensional systems. There are appreciable changes in the absorption spectrum when the electron density or temperature is increased. One interband transition peak is suppressed in the high electron density limit and the thermal depopulation effect on the electron subbands can be easily seen when the temperature is high. We also find that the exciton coupling weakens the shoulder features in the absorption spectrum. This study is relevant to optical characterization of the confining potential and the areal density of electrons using photoreflectance. By using incident light with tunable frequencies in the interband excitation regime, contactless photoreflectance measurements may be carried out and the data compared with our calculations. By fitting the numerical results to the peak positions of the photoreflectance spectrum, the number of electrons in each wire may be extracted.

Article

1998 ◽  
Vol 76 (4) ◽  
pp. 411-413
Author(s):  
Yixing Zhao ◽  
Gordon R Freeman
Keyword(s):  
Absorption Spectrum ◽  
Optical Absorption ◽  
Temperature Dependence ◽  
Optical Absorption Spectrum ◽  
Infrared Light ◽  
Solvated Electron ◽  
Solvated Electrons ◽  
Tert Butanol ◽  
Solvent Dependence ◽  
Increasing Temperature

The energy and asymmetry of the optical absorption spectrum of solvated electrons, es- , change in a nonlinear fashion on changing the solvent through the series HOH, CH3OH, CH3CH3OH, (CH3)2CHOH, (CH3)3COH. The ultimate, quantum-statistical mechanical, interpretation of solvated electron spectra is needed to describe the solvent dependence. The previously reported optical spectrum of es- in tert-butanol was somewhat inaccurate, due to a small amount of water in the alcohol and to limitations of the infrared light detector. The present note records the remeasured spectrum and its temperature dependence. The value of the energy at the absorption maximum (EAmax) is 155 zJ (0.97 eV) at 299 K and 112 zJ (0.70 eV) at 338 K; the corresponding values of G epsilon max (10-22 m2 aJ-1) are 1.06 and 0.74. These unusually large changes are attributed to the abnormally rapid decrease of dielectric permittivity of tert-butanol with increasing temperature. The band asymmetry at 299 K is Wb/Wr = 1.8.Key words: optical absorption spectrum, solvated electron, solvent effects, tert-butanol, temperature dependence.

scholarly journals Monitoring mechanical motion of carbon nanotube based nanomotor by optical absorption spectrum

2016 ◽  
Vol 109 (26) ◽  
pp. 263104 ◽  
Author(s):  
Baomin Wang ◽  
Xuewei Cao ◽  
Zhan Wang ◽  
Yong Wang ◽  
Kaihui Liu
Keyword(s):  
Absorption Spectrum ◽  
Carbon Nanotube ◽  
Optical Absorption ◽  
Optical Absorption Spectrum ◽  
Mechanical Motion

Reversible Changes in the Electronic and Optical Properties of Micro-Crystalline ln2O 3-x: A Comparison with Amorphous In2O3-x

1996 ◽  
Vol 426 ◽  
Author(s):  
B. Pashmakov ◽  
H. Fritzsche ◽  
B. Claflin
Keyword(s):  
Optical Properties ◽  
Optical Absorption ◽  
Absorption Coefficient ◽  
Ultraviolet Light ◽  
Indium Oxide ◽  
Electrical Conductance ◽  
Inert Gas ◽  
Optical Absorption Coefficient ◽  
Electronic And Optical Properties

AbstractThe electrical conductance and optical absorption coefficient of microcrystalline indium oxide (c – In2 O 3-x ) can be changed reversibly by several orders of magnitude by photoreduction and reoxidation. Photoreduction is achieved by exposure to ultraviolet light hv ≥ 3.5eV in vacuum or an inert gas. The effects are similar to those previously observed in amorphous In2 O3-x

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