检索结果-南通市图书馆

Improvement of electro-optic performances in white organic light emitting diodes with color stability by buffer layer and multiple dopants structure

在线全文

学校读者我要写书评

暂无评论

Chinese Physics B 2018年第10期27卷 584-589页

作者：寇志起唐宇杨丽萍杨飞宇郭文军 College of Science University of Shanghai for Science and Technology

A series of white phosphorescent OLED devices with buffer layer and multiple dopant structure is investigated in order to obtain better electro-optic performances and color stability. The color coordinate and color stability are related to the location of multiple dopants layer, and the optimized location can compensate for the change of the blue emission intensity under a high voltage and stabilize the spectrum. The electro-optic performances and color stability can be further improved by changing the composition and thickness of the buffer layer between the emitting layer and the electron transport layer.In device B2, the distance from multiple dopant layer to buffer layer is 2 nm and the thickness of buffer layer is 5 nm,the maximum luminance, current density, and power efficiency can reach 9091 cd/m^2, 364.5 mA/cm^2, and 26.74 lm/W,respectively. The variation of international commission on the illumination（CIE） coordinate of device B2 with voltage increasing from 4 V to 7 V is only（0.006, 0.004）.

关键词： organic light emitting diodes multiple dopants layer buffer layer color stability

Effect of double AlN buffer layer on the qualities of GaN films grown by radio-frequency molecular beam epitaxy

在线全文

学校读者我要写书评

暂无评论

Chinese Physics B 2008年第4期17卷 1360-1363页

作者：李新化钟飞邱凯尹志军姬长建 Key Laboratory of Material Physics Institute of Solid State PhysicsChinese Academy of Sciences

This paper reports that the GaN thin films with Ga-polarity and high quality were grown by radio-frequency molecular beam epitaxy on sapphire （0001） substrate with a double A1N buffer layer. The buffer layer consists of a high-temperature （HT） A1N layer and a low-temperature （LT） A1N layer grown at 800℃ and 600℃, respectively. It is demonstrated that the HT-A1N layer can result in the growth of GaN epilayer in Ga-polarity and the LT-A1N layer is helpful for the improvement of the epilayer quality. It is observed that the carrier mobility of the GaN epilayer increases from 458 to 858cm^2/V.s at room temperature when the thickness of LT-A1N layer varies from 0 to 20nm. The full width at half maximum of x-ray rocking curves also demonstrates a substantial improvement in the quality of GaN epilavers by the utilization of LT-A1N layer.

关键词： Gallium Nitride buffer layer carrier mobility polarity

Role of buffer layer in electronic structures of iron phthalocyanine molecules on Au(111)

在线全文

学校读者我要写书评

暂无评论

Chinese Physics B 2010年第9期19卷 25-30页

作者：孙家涛潘理达胡昊杜世萱高鸿钧 Nanoscale Physics and Devices Laboratory Institute of PhysicsChinese Academy of Sciences

We investigate the electronic structures of one and two monolayer iron phthalocyanine （FePc） molecules on Au（111） surfaces. The first monolayer FePc is lying flat on the Au（111） substrate, and the second monolayer FePc is tilted at -15° relative to the substrate plane along the nearest neighbour [101] direction with a lobe downward to the central hole of the unit cell in the first layer. The structural information obtained by first-principles calculations is in agreement with the experiment results. Furthermore, it is demonstrated that the electronic structures of FePc molecules in one-monolayer FePc/Au（111） system are perturbed significantly, while the electronic structures of FePc molecules in the second monolayer in two-monolayer FePc/Au（111） system remain almost unchanged due to the screening of the buffer layer on Au（111）.

关键词： iron phthalocyanine electronic structure calculations buffer layer

Dip Coating of Nano Hydroxyapatite on Titanium Alloy with Plasma Assistedγ-Alumina buffer layer:A Novel Coating Approach

在线全文

学校读者我要写书评

暂无评论

Journal of Materials Science & Technology 2013年第6期29卷 557-564页

作者： M.Khalid M.Mujahid A.Nusair Khan R.S.Rawat School of Chemical and Materials Engineering National University of Sciences and TechnologySector H-12IslamabadPakistan Institute of Industrial Control Systems RawalpindiPakistan NSSE National Institute of EducationNanyang Technological UniversitySingapore

This paper reported a novel coating approach to deposit a （HA） film on Ti6Al4V alloy with Al2O3 buffer layer for thin, crack free and nano-structured hydroxyapatite biomedical implants. The Al2O3 buffer layer was deposited by plasma spraying while the HA top layer was applied by dip coating technique. The X-ray diffraction （XRD） and Raman reflections of alumina buffer layer showed α- to γ-Al2O3 phase transformation; and the fractographic analysis of the sample revealed the formation of columnar grains in well melted splats. The bonding strength between Al2O3 coating and Ti6Al4V substrate was estimated to be about 40 MPa. The presence of dip coated HA layer was confirmed using XRD, scanning electron microscopy （SEM） and energy dispersive X-ray spectroscopy （EDX） analysis. The SEM images exhibited that HA top layer enveloped homogenously the troughs and crests of the underneath rough （Ra = 2.91 μm） Al2O3 surface. It is believed that the novel coating approach adopted might render the implant suitable for rapid cement-less fixation as well as biocompatible for longer periods.

关键词： Ti6Al4V alloy Biomaterials buffer layer Ceramic coatings

Photocurrent analysis of organic photovoltaic cells based on CuPc/C_(60) with Alq_3 as a buffer layer

在线全文

学校读者我要写书评

暂无评论

Chinese Physics B 2010年第3期19卷 579-583页

作者：王娜娜于军胜臧月蒋亚东 State Key Laboratory of Electronic Thin Films and Integrated Devices School of Optoelectronic InformationUniversity of Electronic Science and Technology of China(UESTC)

The performance of an organic photovoltaic （OPV） cell based on copper phthatocyanine CuPc/C60 with a tris- （8-hydroxyquinolinato） aluminum （Alq3） buffer layer has been investigated. It was found that the power conversion efficiency of the device was 1.51% under illumination with an intensity of 100 mW/cm^2, which was limited by a squareroot dependence of the photocurrent on voltage. The photocurrent optical power density characteristics showed that the OPV cell had a significant space-charge limited photocurrent with a varied saturation voltage and a three quarters power dependence on optical power density. Also, the absorption spectrum was measured by a spectrophotometer, and the results showed that the additional Alq3 layer has a minor effect on photocurrent generation.

关键词： organic photovoltaic （OPV） cells buffer layer Alq3 space-charge limited current

Effects of thin MnAl buffer layer on structural and magnetic properties of MnAl films

在线全文

学校读者我要写书评

暂无评论

Chinese Physics B 2010年第10期19卷 550-553页

作者：张旭辉马斌张宗芝金庆原 Key Lab of Advanced Photonic Materials and Devices Laboratory of Advanced Materials and Department of Optical Science and Engineering Fudan University

Thin Mn（2 nm）/Al（2 nm） bilayers serving as buffer layers have been prepared prior to the deposition of MnAl films. The ferromagnetic T-phase forms in the buffer layers at an optimum substrate temperature. As a template it induces the growth of following MnAl film. Compared with the case of film without buffer layer, the growth of nonferromagnetic phase is suppressed and the structural and magnetic properties of MnAl film are improved. Weak dipolar inter-grain coupling is revealed in the MnAl film, and the magnetic reversal process is dominated by magnetic moment rotation.

关键词： Ll0 τ--MnAl buffer layer

YBCO Films Grown on Sapphire with YSZ buffer layer

在线全文

学校读者我要写书评

暂无评论

Rare Metals 1994年第4期13卷 269-272页

作者：石东奇杨秉川王小平彭正顺常世安北京有色金属研究总院北京

The (h00) oriented YSZ (yttria-stabilized zirconia) buffer layers were grown successfully on (1120) and(1102) sapphire plane substrates by rf. planar target magnetron sputtering method. The effect of different dep-osition conditions on the structure of YSZ films was studied X-ray diffraction rock curve and electron channel-ling pattern (ECP) showed that the YSZ films has highly oriented nature. YBCO (Y BaCuO) films were depos-ited on the YSZ / (1120) Al_2O_3 and (1102) Al_2O_3, substrate by in situ de inverted cyhdrical target magnetronsputtering method. T_c≥88K and J_c=1O × 10￣6A / cm￣2 at 77 K were achieved

关键词： YBaCuO film Yttria-stabilized zirconia buffer layer

First-principles study of the growth and diffusion of B and N atoms on the sapphire surface with h-BN as the buffer layer

在线全文

学校读者我要写书评

暂无评论

Journal of Semiconductors 2021年第8期42卷 66-72页

作者： Jianyun Zhao Xu Li Ting Liu Yong Lu Jicai Zhang College of Mathematics and Physics Beijing University of Chemical TechnologyBeijing 100029China State Key Laboratory of Chemical Resource Engineering Beijing University of Chemical TechnologyBeijing 100029China

Currently,the preparation of large-size and high-quality hexagonal boron nitride is still an urgent problem.In this study,we investigated the growth and diffusion of boron and nitrogen atoms on the sapphire/h-BN buffer layer by first-principles calculations based on density functional theory.The surface of the single buffer layer provides several metastable adsorption sites for free B and N atoms due to exothermic reaction.The adsorption sites at the ideal growth point for B atoms have the lowest adsorption energy,but the N atoms are easily trapped by the N atoms on the surface to form N-N bonds.With the increasing buffer layers,the adsorption process of free atoms on the surface changes from exothermic to endothermic.The diffusion rate of B atoms is much higher than that of the N atoms thus the B atoms play a major role in the formation of B-N bonds.The introduction of buffer layers can effectively shield the negative effect of sapphire on the formation of B-N bonds.This makes the crystal growth on the buffer layer tends to two-dimensional growth,beneficial to the uniform distribution of B and N atoms.These findings provide an effective reference for the h-BN growth.

关键词： hexagonal boron nitride buffer layer first-principles calculations molecular dynamics

Influence of buffer-layer Thickness on Performance of Waveguide Modulators

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Lasers 1996年第2期5卷 157-162页

作者： XAING Yunnan WANG Kuiru YU Guoxian XU Daxiong (Beijing Unversity of Post and Telecommunications ,Department of Applied Science and Technology , Beijing 100088, China)

ＩｎｆｌｕｅｎｃｅｏｆＢｕｆｆｅｒ－ＬａｙｅｒＴｈｉｃｋｎｅｓｓｏｎＰｅｒｆｏｒｍａｎｃｅｏｆＷａｖｅｇｕｉｄｅＭｏｄｕｌａｔｏｒｓ￥ＸＡＩＮＧＹｕｎｎａｎ；ＷＡＮＧＫｕｉｒｕ；ＹＵＧｕｏｘｉａｎ；ＸＵＤａｘｉｏｎｇ... 详细信息

ＩｎｆｌｕｅｎｃｅｏｆＢｕｆｆｅｒ－ＬａｙｅｒＴｈｉｃｋｎｅｓｓｏｎＰｅｒｆｏｒｍａｎｃｅｏｆＷａｖｅｇｕｉｄｅＭｏｄｕｌａｔｏｒｓ￥ＸＡＩＮＧＹｕｎｎａｎ；ＷＡＮＧＫｕｉｒｕ；ＹＵＧｕｏｘｉａｎ；ＸＵＤａｘｉｏｎｇ（ＢｅｉｊｉｎｇＵｎｖｅｒｓｉｔｙ...

关键词： waveguide modulator buffer layer point matching method polarization independent modulator