scholarly journals Lattice Dynamics and the Optical Properties of Semiconductors: Theory of the Temperature Dependent Dielectric Functions of GaAs and Si and Comparison with Experiment

2010 ◽  
Author(s):  
Z. A. Ibrahim ◽  
A. I. Shkrebtii ◽  
M. J. G. Lee ◽  
T. Teatro ◽  
M. Drago ◽  
...  
Keyword(s):  
Optical Properties ◽  
Lattice Dynamics ◽  
Temperature Dependent ◽  
Comparison With Experiment

Temperature dependent electron–phonon coupling of Au resolved via lattice dynamics measured with sub-picosecond infrared pulses

2021 ◽  
Vol 129 (19) ◽  
pp. 193104
Author(s):  
John A. Tomko ◽  
Sushant Kumar ◽  
Ravishankar Sundararaman ◽  
Patrick E. Hopkins
Keyword(s):  
Lattice Dynamics ◽  
Phonon Coupling ◽  
Temperature Dependent ◽  
Electron Phonon Coupling

scholarly journals Temperature-Dependent Photoluminescence of ZnO Thin Films Grown on Off-Axis SiC Substrates by APMOCVD

Materials ◽  
2021 ◽  
Vol 14 (4) ◽  
pp. 1035
Author(s):  
Ivan Shtepliuk ◽  
Volodymyr Khranovskyy ◽  
Arsenii Ievtushenko ◽  
Rositsa Yakimova
Keyword(s):  
Optical Properties ◽  
Structural Quality ◽  
Organic Chemical ◽  
Zno Films ◽  
Vicinal Surfaces ◽  
Temperature Dependent ◽  
Step Flow ◽  
Step Flow Growth ◽  
First Time ◽  
Temperature Dependent Photoluminescence

The growth of high-quality ZnO layers with optical properties congruent to those of bulk ZnO is still a great challenge. Here, for the first time, we systematically study the morphology and optical properties of ZnO layers grown on SiC substrates with off-cut angles ranging from 0° to 8° by using the atmospheric pressure meta–organic chemical vapor deposition (APMOCVD) technique. Morphology analysis revealed that the formation of the ZnO films on vicinal surfaces with small off-axis angles (1.4°–3.5°) follows the mixed growth mode: from one side, ZnO nucleation still occurs on wide (0001) terraces, but from another side, step-flow growth becomes more apparent with the off-cut angle increasing. We show for the first time that the off-cut angle of 8° provides conditions for step-flow growth of ZnO, resulting in highly improved growth morphology, respectively structural quality. Temperature-dependent photoluminescence (PL) measurements showed a strong dependence of the excitonic emission on the off-cut angle. The dependences of peak parameters for bound exciton and free exciton emissions on temperature were analyzed. The present results provide a correlation between the structural and optical properties of ZnO on vicinal surfaces and can be utilized for controllable ZnO heteroepitaxy on SiC toward device-quality ZnO epitaxial layers with potential applications in nano-optoelectronics.

PERMITTIVITY IN PERTURBED MOLECULAR NANOFILMS

2012 ◽  
Vol 26 (15) ◽  
pp. 1250078 ◽  
Author(s):  
BRANKO MARKOSKI ◽  
JOVAN P. ŠETRAJČIĆ ◽  
MIROSLAVA PETREVSKA ◽  
SINIŠA VUČENOVIĆ
Keyword(s):  
Optical Properties ◽  
Dielectric Properties ◽  
Green's Functions ◽  
Green’S Functions ◽  
Microscopic Theory ◽  
2D Systems ◽  
Molecular Films ◽  
Temperature Dependent

A microscopic theory of dielectric properties of thin molecular films, i.e., quasi 2D systems bounded by two surfaces parallel to XY planes was formulated. Harmonic exciton states were calculated using the method of two-time, retarded, temperature dependent Green's functions. It has been shown that two types of excitations can occur: bulk and surface exciton states. Analysis of the optical properties of these crystalline systems for low exciton concentration shows that the permittivity strongly depends on boundary parameters and the thickness of the film. Conditions for the appearance of localized or unoccupied exciton states have been especially analyzed.

scholarly journals Temperature dependent optical properties of amorphous silicon for diode laser crystallization

2012 ◽  
Vol 20 (S6) ◽  
pp. A856 ◽  
Author(s):  
Joachim Bergmann ◽  
Martin Heusinger ◽  
Gudrun Andrä ◽  
Fritz Falk
Keyword(s):  
Optical Properties ◽  
Amorphous Silicon ◽  
Diode Laser ◽  
Laser Crystallization ◽  
Temperature Dependent

Temperature-dependent optical properties of hexagonal and cubic MgxZn1 xO thin-film alloys

2004 ◽  
Vol 16 (17) ◽  
pp. 2973-2980 ◽  
Author(s):  
N B Chen ◽  
H Z Wu ◽  
D J Qiu ◽  
T N Xu ◽  
J Chen ◽  
...  
Keyword(s):  
Thin Film ◽  
Optical Properties ◽  
Temperature Dependent

OPTICAL PROPERTIES OF CdTe AND CdS QUANTUM DOTS IN GLASS

1992 ◽  
Vol 01 (01) ◽  
pp. 25-50 ◽  
Author(s):  
V. ESCH ◽  
K. KANG ◽  
B. FLUEGEL ◽  
Y.Z. HU ◽  
G. KHITROVA ◽  
...  
Keyword(s):  
Quantum Dots ◽  
Optical Properties ◽  
Optical Nonlinearities ◽  
Cds Quantum Dots ◽  
Temperature Dependent ◽  
Linear Absorption ◽  
Crystallite Sizes ◽  
Band Mixing ◽  
Quantum Confined ◽  
Coulomb Effects

We summarize the linear and nonlinear optical properties of a variety of CdTe and CdS quantum dots in glass. The measured linear absorption of the CdTe sample is compared with calculations involving valence-band mixing due to the quantum confinement. The temperature dependence of the lowest quantum-confined transition and its linewidth for samples with various crystallite sizes are measured and compared with a simple model. It is found that the shift of the energetically lowest quantum-confined transition as a function of temperature is the same as the temperature-dependent band-gap reduction in bulk materials. Excitation of the sample with pulses ranging from femtoseconds to microseconds allows distinguishing between various mechanisms responsible for the observed optical nonlinearities. At very early times, phase-space filling and Coulomb interaction between the excited charged carriers are responsible for the absorption changes. At later times, Coulomb effects due to “trapped” carriers remain and last for nanoseconds or microseconds.

scholarly journals Unconventional Optical Response in Engineered Au-Ag Nanostructures

2019 ◽  
Author(s):  
Dev Kumar Thapa ◽  
Subham Kumar Saha ◽  
Guru Pratheep Rajasekar ◽  
Biswajit Bhattacharyya ◽  
Rekha Mahadevu ◽  
...  
Keyword(s):  
Optical Properties ◽  
Surface Plasmon ◽  
Mie Theory ◽  
Localized Surface Plasmon ◽  
Silver Particles ◽  
Temperature Dependent ◽  
Surface Plasmon Resonances ◽  
Localized Surface Plasmon Resonances ◽  
Plasmon Resonances ◽  
Diamagnetic State

This article describes the optical properties of nanostructures composed of silver particles embedded into a gold matrix. In previous studies these materials were shown to exhibit temperature dependent transitions to a highly conductive and strongly diamagnetic state. Here we describe the anomalous optical properties of these nanostructures. Most notably, these materials fail to obey Mie theory and exhibit an unconventional resonance with a maximum at about 4 eV, while the usual gold and silver localized surface plasmon resonances are suppressed. This effect implies a significant deviation from the bulk dielectric functions of gold and silver. We further resolved this resonance into its absorbance and scattering sub-parts. It is observed that the resonance is largely comprised of scattering, with negligible losses even at ultraviolet frequencies.

scholarly journals The temperature-dependent optical properties of ZnO film deposited on sapphire fiber-ending

2009 ◽  
Vol 58 (4) ◽  
pp. 2792
Author(s):  
Sui Cheng-Hua ◽  
Cai Ping-Gen ◽  
Chen Nai-Bo ◽  
Wei Gao-Yao ◽  
Xu Xiao-Jun ◽  
...  
Keyword(s):  
Optical Properties ◽  
Zno Film ◽  
Temperature Dependent ◽  
Sapphire Fiber
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