scholarly journals Substrate-Dependent Differences in the Crystal Structures and Optical Properties of ZnSe Nanowires

2015 ◽  
Vol 2015 ◽  
pp. 1-6
Author(s):  
Keumyoung Seo ◽  
Jihye Bong ◽  
Jae-Woo Kim ◽  
Yoon-Ho Song ◽  
Yong Ho Shin ◽  
...  
Keyword(s):  
Optical Properties ◽  
Structural Properties ◽  
Field Emission ◽  
Hexagonal Structure ◽  
Emission Peak ◽  
Photoluminescence Spectra ◽  
Red Emission ◽  
Light Emitting ◽  
Znse Nanowires ◽  
Emission Light

The optical and structural properties of ZnSe nanowires directly grown on three different substrates, SiO2, ITO, and graphene, were investigated. ZnSe nanowires grown on graphene and SiO2were found to have cubic structures, while ZnSe nanowires grown on ITO had a mixed cubic and hexagonal structure. The main peaks in the photoluminescence spectra of ZnSe nanowires grown on SiO2, ITO, and graphene were located at 459, 627, and 627/460 nm, respectively. In addition, a field-emission light-emitting device was fabricated using ZnSe nanowires as a phosphor and graphene as an electrode. The device showed a red emission peak with Commission Internationale de L’Eclairage coordinates of (0.621, 0.315).

Unusual Terpyridines as Ligands for Novel Light-Emitting Iridium(III) Complexes: Synthesis and Characterization

2006 ◽  
Vol 59 (11) ◽  
pp. 773 ◽  
Author(s):  
Andreas Winter ◽  
Christoph Ulbricht ◽  
Elisabeth Holder ◽  
Nikolaus Risch ◽  
Ulrich S. Schubert
Keyword(s):  
Mass Spectrometry ◽  
Optical Properties ◽  
Nmr Spectroscopy ◽  
Splitting Method ◽  
Synthesis And Characterization ◽  
Two Dimensional ◽  
Photoluminescence Spectra ◽  
Light Emitting ◽  
Yellow Orange ◽  
Terpyridine Ligands

Based on S-shaped terpyridines, a series of yellow, orange, and red-orange light-emitting iridium(iii) complexes has been synthesized. The respective compounds have been prepared by the bridge-splitting method starting from the dimeric precursor complexes [(ppy)2Ir-μ-Cl]2, [(ppy-CHO)2Ir-μ-Cl]2, and [(c6)2Ir-μ-Cl]2. The products have been fully characterized by one- and two-dimensional (1H–1H correlation) NMR spectroscopy, elemental analysis, and MALDI-TOF mass spectrometry revealing the successful coordination of the iridium(iii) centres to the S-shaped terpyridine ligands. Furthermore, the quantitative coordination has been verified by the photophysical and electrochemical properties of the mononuclear iridium(iii) complexes. The photoluminescence spectra have shown strong emissions with maxima between 538 and 600 nm. The study of the optical properties of these novel complexes has indicated that the colour shifts are mainly depending on the nature of the cyclometallating ligands.

Optical Properties of Co-Doped Zno Nano Powder Material Prepared by Ball Milling

2011 ◽  
Vol 143-144 ◽  
pp. 190-193
Author(s):  
Song Ning Xu ◽  
Z.Q. Cai ◽  
N.K. Sun ◽  
Y.B. Gao ◽  
F. Liu
Keyword(s):  
Crystal Structure ◽  
Optical Properties ◽  
Ball Milling ◽  
Blue Emission ◽  
Peak Position ◽  
Hexagonal Structure ◽  
Photoluminescence Spectra ◽  
Doped Zno ◽  
Zno Crystal ◽  
Co Doped

Zn1-xCoxO nano powders have been successfully prepared by ball milling and have been annealing at 600°C. The crystal structure and optical properties of sample were characterized by X-ray diffraction (XRD), photoluminescence spectra (PL) and ultraviolet visible light absorption spectra (UV), and the formation mechanism was discussed. Co-doped ZnO nano powders exhibit wurtzite (hexagonal) structure. Co2+enters into ZnO crystal structure and substitutes for Zn2+. All samples show typical luminescence behavior with about 396nm UV emission peak. In addition, the about 450nm and 470nm blue emission peaks are found in photoluminescence spectra. Before the doped content is within 8at%, the band edge of ultraviolet absorption appears red shift phenomenon with the increase of doping content. The peak position was shifted from 362nm (3.43eV) to 367nm (3.38eV). Annealing is in favor of the replacement that Co2+enters into ZnO crystal structure and substitutes for Zn2+

The Emission Property of Phosphors LEDs Based on ZnCuInS/ZnSe/ZnS Quantum Dots

2014 ◽  
Vol 989-994 ◽  
pp. 623-625
Author(s):  
Ke Bi ◽  
Wen Yan Liu ◽  
Tian Yue Xu ◽  
Tie Qiang Zhang ◽  
Yu Zhang
Keyword(s):  
Quantum Dots ◽  
Photoluminescence Spectrum ◽  
Stokes Shift ◽  
Core Shell ◽  
Photoluminescence Properties ◽  
Red Emission ◽  
Light Emitting ◽  
Quantum Size ◽  
Gan Led ◽  
Photoluminescence Peak

.In this research, ZnCuInS/ZnSe/ZnS quantum dots (QDs) have been studied as an excellent red emitting source for blue GaN LED because of its non-toxic deep red emmission, and large Stokes shift properties. In the paper ZnCuInS/ZnSe/ZnS core/shell quantum dots were prepared with the particle size of 4.5nm. According to the measurement of photoluminescence spectrum emitted by ZnCuInS/ZnSe/ZnS core/shell quantum dots, the emitting peak of 700 nm and the full was achieved as red emitter.It was found that absorption edge and photoluminescence peak shifted to shorter wavelength with decreasing the nanocrystal size due to quantum size effect.Meanwhile, we were prepared ZnCuInS/ZnSe/ZnS core/shell quantum dot light emitting diodes and their photoluminescence properties were studied. After the suitable bias was applied on the films, increasing the ZnCuInS/ZnSe/ZnS QDs concentration in the blue GaN chips, red emission increased with decreasing LED’s blue light.

Electrical and Optical Properties of Si+ and P+ Implanted InP:Fe

1990 ◽  
Vol 201 ◽  
Author(s):  
Honglie Shen ◽  
Genqing Yang ◽  
Zuyao Zhou ◽  
Guanqun Xia ◽  
Shichang Zou
Keyword(s):  
Optical Properties ◽  
Silicon Nitride ◽  
Temperature Dependence ◽  
Optimal Condition ◽  
Room Temperature ◽  
Broad Band ◽  
Photoluminescence Spectra ◽  
Electrical And Optical Properties ◽  
Spectrum Measurement ◽  
Single Implant

AbstractDual implantations of Si+ and P+ into InP:Fe were performed both at 200°C and room temperature. Si+ ions were implanted by 150keV with doses ranging from 5×1013 /cm2 to 1×1015 /cm2, while P+ ions were implanted by 110keV. 160keV and 180keV with doses ranging from 1×l013 /cm2 to 1×1015 /cm2. Hall measurements and photoluminescence spectra were used to characterize the silicon nitride encapsulated annealed samples. It was found that enhanced activation can be obtained by Si+ and P+ dual implantations. The optimal condition for dual implantations is that the atomic distribution of implanted P overlaps that of implanted si with the same implant dose. For a dose of 5×l014 /cm2, the highest activation for dual implants is 70% while the activation for single implant is 40% after annealing at 750°C for 15 minutes. PL spectrum measurement was carried out at temperatures from 11K to 100K. A broad band at about 1.26eV was found in Si+ implanted samples, of which the intensity increased with increasing of the Si dose and decreased with increasing of the co-implant P+ dose. The temperature dependence of the broad band showed that it is a complex (Vp-Sip) related band. All these results indicate that silicon is an amphoteric species in InP.

OPTICAL PROPERTIES OF GaInN/GaN MULTI-QUANTUM WELL STRUCTURE AND LIGHT EMITTING DIODE GROWN BY METALORGANIC CHEMICAL VAPOR PHASE EPITAXY

2007 ◽  
Vol 17 (01) ◽  
pp. 81-84
Author(s):  
J. Senawiratne ◽  
M. Zhu ◽  
W. Zhao ◽  
Y. Xia ◽  
Y. Li ◽  
...  
Keyword(s):  
Optical Properties ◽  
Quantum Well ◽  
Stark Effect ◽  
Light Emitting Diode ◽  
Chemical Vapor ◽  
Green Emission ◽  
Luminescence Spectroscopy ◽  
Light Emitting ◽  
Quantum Confined Stark Effect ◽  
Multi Quantum Well

Optical properties of green emission Ga 0.80 In 0.20 N/GaN multi-quantum well and light emitting diode have been investigated by using photoluminescence, cathodoluminescence, electroluminescence, and photoconductivity. The temperature dependent photoluminescence and cathodoluminescence studies show three emission bands including GaInN/GaN quantum well emission centered at 2.38 eV (~ 520 nm). The activation energy of the non-radiative recombination centers was found to be ~ 60 meV. The comparison of photoconductivity with luminescence spectroscopy revealed that optical properties of quantum well layers are strongly affected by the quantum-confined Stark effect.

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