Structure and Optical Properties

Cohen M L and Cheiikowsky J R 1989 Electronic Structure and Optical Properties of Semiconductors 2nd edn (Springer)... 

Sarangi, S. N. and Sahu, S. N. (2004). CdSe nanocrystalline thin films composition, structure and optical properties. Physica E, 23,159-167. 

Structural and optical properties of luGaN/GaN triangularshaped quantum wells grown by metalorganic chemical vapor depostion... 

The crystal quality of the InGaN QWs becomes poor mainly due to the lattice-constant mismatch and the difference of the thermal expansion coefficient between InN and GaN with increasing the In composition [4,5]. Therefore, in order to improve the external quantum efficiency (i/ext) of the InGaN-based LEDs and LDs, it is important to elucidate and optimize the effects of the various growth conditions for the InGaN active layer on the structural and optical properties. Recently, we reported a fabrication of efficient blue LEDs with InGaN/GaN triangular shaped QWs and obtained a substantial improvement of electrical and optical properties of the devices [6,7]. 

In this paper, we report the structural and optical properties of InxGai-xN/GaN triangular shaped MQWs obtained under various conditions of growth variables. In addition, the emission mechanism of the InGaN QWs is intensively discussed. 

In this study, we report on the GaN nanorod growth by HOMVPE technique with or without using a new precursor, tris(N,N-dimethyldithiocarbamato)gallium(III) (Ga(mDTC)3). The structural and optical properties of GaN nanorods were characterized by x-ray diffraction (XRD), scanning electron microscopy (SEM), and photoluminescence (PL). 

Kainthla RC, Pandya DK, Chopra KL (1982) Structural and optical properties of solution grown CdSei xSx films. J Electrochem Soc 129 99-102... 

Mishina, E. D., Nagai, K. and Nakabayashi, S. (2001) Self-assembled CU/CU2O multilayers Deposition, structure and optical properties. Nano Lett., 1, 401 104. 

Gauthier G, Jobic S, Evain M, Koo HJ, Whangbo MH, Fouassier C, Brec R (2003) Synthesis, structures and optical properties of yellow Ce2SiS5 Ce6Si4S17, and Ce4Si3S12 materials. Chem Mater 15 828-837... 

Main structural and optical properties of conjugated polymers... 

W.M. Becker, Band Structure and Optical Properties of Wide-Gap A 1MnJ[BVI Alloys at Zero Magnetic Field... 

Soliman, H. S. 1998. Structural and optical properties of thin films of CuGaS2. /. Phys. D Appl. Phys. 31 1516-1521. 

Dhanam, M. Balasundaraprabhu, R. Jayakumar, S. Gopalakrishnan, R Kannan, M. D. 2002. Preparation and study of structural and optical properties of chemical... 

Sartale, S. D. Lockhande, C. D. 2001. Effect of annealing on the structural and optical properties of SILAR grown CuxS thin films. Indian J. Phys. 75A 375-378. 

To sum up, the analytical mode proposed presents a rare instance when a rather simple treatment enables not only qualitative but also quantitative relationships between structure and optical properties to be revealed. 

SCHEME 3.25 Chemical structures and optical properties of Alq3 derivatives (maximum emission wavelength, photoluminescent quantum efficiency in CH2C12 and the band gap are listed). 

Chirality (or a lack of mirror symmetry) plays an important role in the LC field. Molecular chirality, due to one or more chiral carbon site(s), can lead to a reduction in the phase symmetry, and yield a large variety of novel mesophases that possess unique structures and optical properties. One important consequence of chirality is polar order when molecules contain lateral electric dipoles. Electric polarization is obtained in tilted smectic phases. The reduced symmetry in the phase yields an in-layer polarization and the tilt sense of each layer can change synclinically (chiral SmC ) or anticlinically (SmC)) to form a helical superstructure perpendicular to the layer planes. Hence helical distributions of the molecules in the superstructure can result in a ferro- (SmC ), antiferro- (SmC)), and ferri-electric phases. Other chiral subphases (e.g., Q) can also exist. In the SmC) phase, the directions of the tilt alternate from one layer to the next, and the in-plane spontaneous polarization reverses by 180° between two neighbouring layers. The structures of the C a and C phases are less certain. The ferrielectric C shows two interdigitated helices as in the SmC) phase, but here the molecules are rotated by an angle different from 180° w.r.t. the helix axis between two neighbouring layers. 

A detailed study of the electronic structure and optical properties was published for the spiro derivative of f-Bu-PBD, Spiro-PBD (40) [108]. The vibronic structure of the lowest energy absorption band is well resolved, in solution as well as in the amorphous him. The 0-0 transition is at 351 nm (3.53 eV), the 0-1 and 0-2 vibronic bands that have a higher oscillator strength, are at 336 nm (3.69 eV) and 318 nm (3.90 eV), respectively. The fluorescence spectrum of this compound is symmetrical to the absorption spectrum with a Stokes shift of 43 nm. 

Cohen, M.L. Chelikowsky, J.R. Electronic Structure and Optical Properties of Semiconductors Springer-Verlag, Berlin, 1988. 

B. W., Effect of carbon modification on the electrical, structural, and optical properties of Ti02 electrodes and their performance in labscale dye-sensitized solar cells. Int.J. Photoenergy 2012, 904323/1-9. 

Asanuma T, Matsutani T, Liu G, Mihara T, Kiuchi M (2004) Structural and optical properties of titanium dioxide films deposited by reactive magnetron sputtering in pure oxygen plasma. J Appl Phys 95 6011-6016... 

The laser recorded information is preserved for a long time if the sample is cooled below Tg. From this viewpoint LC polymers differ usefully from low-molecular liquid crystals. The information storage time in the devices based on low-molecular liquid crystals do not usually exceed a few days. The described effects demonstrate the capabilities for the control of structural and optical properties of LC polymeric materials. 

Leem, J.-Y., Jeon, M., Lee, J. el al. (2003) Influence of GaAs/InAs quasi-monolayer on the structural and optical properties of InAs/GaAs quantum dots. Journal of Crystal Growth, 252(4), 493-98. 

Mashraqui et al. [63] reported the synthesis of dithia-bridged cyclophanes incorporating thienol 2,3 %J thiophene as one of the rings, and investigated their structures and optical properties. The synthetic route affording compounds 240-244 is shown in Scheme 49. 

Theoretical calculations of the electronic structure and optical properties of H-passivated Si quantum wires have been reported by a number of research groups (see, for example, Ref. 116 and references therein). First principles calculations show the same band nesting phenomenon and near-flat dispersion along the T-Z symmetry (wire) direction, as described above for Si quantum wells, and the occurrence of direct gaps.116,117... 

In the above sections, our attention was primarily focused on the structural and optical properties of lanthanide doped in nanoparticles such as spherical QDs. Lanthanides doped in some other novel low-dimensional nanostructures including core-shell, one-dimensional (ID) nanowires and nanotubes, two-dimensional (2D) nanofilms, hollow nanospheres, 2D nanosheets and nanodisks have also attracted extensive attention. It is expected that their unique structures could result in unusual mechanical, electronic, optical and magnetic properties. So far few papers have been reported for lanthanide ions other than Eu3+ in these materials. Much attention is focused on the optical properties of Eu3+ ions in view of their very good spectroscopic properties. 

Eli Y2O3 nanolayers coated on different dielectric nanoparticles Recently, the structural and optical properties of Eu3+ Y2C>3 films coated on a variety of dielectric nanoparticles have been investigated using transmission electron microscope (TEM), X-rays diffraction (XRD) and site-selective laser spectroscopic methods (Chen, X.Y. et al., 2005 Chen et al., 2003a). Eu3+ ions are employed as probes for the study of crystallization and multi-site structure as well as the luminescent centers in nanolayers. It was found that the luminescent nanolayers exhibit distinct thermodynamics and luminescence properties. 

Ambrosch-Draxl, C., Majewski, J.A., Vogl, P. and Leising, G. (1995) First-prindples studies of the structural and optical properties of crystalline poly (para-phenylene). Physical Review. B, Condensed Matter, 51, 9668-76. 

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