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Search Results: 1 - 10 of 10325 matches for " Optical Property "
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Preparation and Optical Properties Assessment of CdSe Quantum Dots  [PDF]
Gholam Reza Amiri, Soheil Fatahian, Somayeh Mahmoudi
Materials Sciences and Applications (MSA) , 2013, DOI: 10.4236/msa.2013.42015

CdSe quantum dots (QDs) (2 - 3 nm) were synthesized by chemical precipitation method. Optical and structure properties of the products were investigated by scanning tunneling microscope (STM), X-ray diffraction (XRD), and ultra violet-visible (UV-Vis) spectrophotometer. The results show that high-quality cubic CdSe QDs were obtained. It is also obtained that temperature is one of the most important factors the affect on the particle size and optical properties of the prepared QDs samples.

Optical Properties of the Coupling Interface for Planar Optical Waveguides  [PDF]
Yu Zheng, Ji-An Duan
Optics and Photonics Journal (OPJ) , 2011, DOI: 10.4236/opj.2011.13018
Abstract: Planar optical waveguides are the key elements in a modern, high-speed optical network. An important problem facing the optical fiber communication system, specifically planar optical waveguides, is coupling. The current study presents a coupling model for planar optical waveguides and optical fibers. The various effects of the optical properties of the coupling interface were analyzed by the scalar finite difference beam propagation method, including the thickness, with or without the matching refractive index of the interface adhesive. The findings can serve as a guide for planar optical waveguide packaging.
Synthesis and Characterization of CeO2 Nanocrystals by Solvothermal Route
Kumar, E.;Selvarajan, P.;Muthuraj, D.;
Materials Research , 2013, DOI: 10.1590/S1516-14392013005000021
Abstract: cerium dioxide nanoparticles were prepared by solvothermal technique. the structural analysis was carried out using x-ray diffraction. it showed that the cerium dioxide nanoparticles exhibited cubic structure. grain sizes were estimated from high resolution transmission electron microscopy images. the size of the nanoparticles is around 20 nm. the surface morphological studies from scanning electron microscope (sem) and hrtem depicted spherical particles with formation of clusters. thermal and electrical insulating behaviors were determined.
Synthesis and Spectroscopic Properties of Ferrocenyl Derivative Containing Donor and Acceptor Groups  [PDF]
Makoto Minato, Chiharu Sorai, Takashi Ito, Masashi Kiguchi, Midori Kato
International Journal of Organic Chemistry (IJOC) , 2017, DOI: 10.4236/ijoc.2017.73022
Abstract: Much interest has been devoted to organometallic NLO materials. We have become interested in exploring the utility of ferrocenyl group as the conjugating bridge. Thus, we synthesized 1-{{[1,3-(5-methylbenzo)dithiol]-2-yli- dene}methyl}-1’-[2-(p-nitrophenyl)-(E)-ethenyl]ferrocene (1). This new ferrocenyl compound has a donor and an acceptor group in 1,1’-positions. Investigations of the solvatochromic property of the compound revealed that it has polarized structure in a polar solvent, such as DMF. SHG efficiency of the compound was estimated by an SHEW (second-harmonic generation with the evanescent wave) method.
Fabrication and Characterization of Bulk Heterojunction Solar Cells Based on Liquid-Crystal Semiconductive Polymer  [PDF]
Atsushi Suzuki, Shinichi Ogahara, Tsuyoshi Akiyama, Takeo Oku
Energy and Power Engineering (EPE) , 2012, DOI: 10.4236/epe.2012.46060
Abstract: Bulk heterojunction solar cells based on poly poly(9,9-dioctylfluorene-co-bithiophene) (F8T2) as liquid crystal semiconductive polymer and C60 as electron acceptor were fabricated and characterized. Thermal treatment of the bulk heterojunction films at annealing in the range of glass temperature and liquid crystal transition was performed for tuning optimization with improving the photovoltaic and optical properties. The photovoltaic performance was depended on morphological behavior in active layer at crystal state below glass temperature. The F8T2 thin film worked for electron-donor layer as p-type semiconductor to support charge transfer in active layer. Mechanisms of the photovoltaic properties were discussed on the basis of experimental results.
Density-functional theory investigation of energy gaps and optical properties of Hg1-xCdxTe and In1-xGaxAs

Guo San-Dong,Liu Bang-Gui,

中国物理 B , 2012,
First-principles calculations for electronic, optical and thermodynamic properties of ZnS

Hu Cui-E,Zeng Zhao-Yi,Cheng Yan,Chen Xiang-Rong,Cai Ling-Cang,

中国物理 B , 2008,
Abstract: The electronic, optical and thermodynamic properties of ZnS in the zinc-blende (ZB) and wurtzite (WZ) structures are investigated by using the plane-wave pseudopotential density functional theory (DFT). The results obtained are consistent with other theoretical results and the available experimental data. When the pressures are above 20.5 and 27\,GPa, the ZB-ZnS and the WZ-ZnS are converted into indirect gap semiconductors, respectively. The critical point structure of the frequency-dependent complex dielectric function is investigated and analysed to identify the optical transitions. Moreover, the values of heat capacity $C_{V}$ and Debye temperature {$\Th$} at different pressures and different temperatures are also obtained successfully.
Investigation of Nickel Phthalocyanine Thin Films for Solar Cell Applications  [PDF]
Eman M. Nasir, Mohammed T. Hussein, Addnan H. Al-Aarajiy
Advances in Materials Physics and Chemistry (AMPC) , 2019, DOI: 10.4236/ampc.2019.98013
Ni-Phthalocyanine thin films were thermally evaporated with different substrate temperatures (300 - 450) K on (silicon wafer, glass) substrates. The chemical bonds of NiPc powder were investigated by FTIR spectrum, which introduce good information for NiPc bonds and their locations. The optical properties have been studied by UV-Visible, and Photoluminescence (PL) Spectra. The NiPc thin films have direct gap for all samples. The values of energy gap which is calculated by PL spectra are lower than those calculated by Tauc equation. It is found there are three activation energies, the mobility and concentration of carriers have been measured and, the NiPc films are p-type. P-NiPc/n-Si HJ solar cell was fabricated at substrates temperatures (300, 400) K. From I-V and C-V characteristic, abrupt junction has been found, photovoltaic characteristics have been observed with Voc of (0.335 - 0.415) V, and Isc of (2.77 - 4.26) μA, and the efficiency of (3.08 - 5.03)% at room temperature and substrate temperature (300, 400 K) and under illumination of 55 mW/cm2 using Halogen lamp. Ideality factors of the junction increase from (0.61 - 0.73) and barrier height increases from 2.53 eV to
Optical, Photophysical, Stability and Mirrorless Lasing Properties of Novel Fluorescein Derivative Dye in Solution  [PDF]
Maram T. H. Abou-Kana
Open Journal of Applied Sciences (OJAppS) , 2012, DOI: 10.4236/ojapps.2012.24034
Abstract: Novel laser dye, allyl 2-(6-(allyloxy)-3-oxo-3H-xanthen-9-yl) benzoate [diallyl-fluorescein] has been synthesized. Its chemical structure was confirmed by 1HNMR, IR, MS and elemental analysis. Its optical properties were experimentally investigated. The amplified spontaneous emission (ASE) efficiency was 0.29% in case of new dye while it was 0.23% in case of fluorescein by pumping the dye samples with a 532 nm (7 ns) pulsed Nd:YAG laser. Also, the thermal and photostability techniques confirmed the higher stability of new laser dye.
Ground-based observation of aerosol optical properties in Lanzhou, China

YU Xingna,ZHU Bin,FAN Shuxian,YIN Yan,BU Xiaoli,

环境科学学报(英文版) , 2009,
Abstract: Aerosol optical properties from August 2006 to July 2007 were obtained from ground-based and sky radiance measurements in Semi-Arid Climate and Environment Observatory of Lanzhou University (SACOL),China.Higher aerosol optical thickness (AOT) associated with lower (A)ngstr(O)m exponent (α) was mainly observed in spring,which was consistent with the seasonal dust production from Hexi Corridor.The maximum monthly average of AOT 0.56 occurred in March of 2007,which was two times larger than the minimum 0.28 in October of 2006.Approximately 60% of the AOT ranged between 0.3 and 0.5,and nearly 93% of α varied from 0.1 to 0.8 occurred in spring.The significant correlation between aerosol properties and water vapor content was not observed.The aerosol volume size distribution can be characterized by the bimodal logarithm normal structure: fine mode (r < 0.6 μm) and coarse mode (r > 0.6 μm).Aerosols in spring of SACOL were dominated by large particles with the volume concentration ratio of coarse to fine modes being 7.85.The averages of asymmetry factor (ɡ) in the wavelength range 440-1020 nm were found to be 0.71,0.67,0.67 and 0.69 in spring,summer,autumn and winter,respectively.
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