化学镀金在GaN基发光二极管电极制备上的应用

采用真空蒸镀与化学镀两种方法制备GaN基发光二极管（LED）金电极,分析比较了两种工艺所得芯片成本、外观色差、打线拉力。结果表明,化学镀金可选择性还原欲沉积的金属于电极上,较之蒸镀整面金属,可大幅度节省金属成本,且操作简单易行。化学镀金法所制得金属层,较蒸镀法所制得金属层表面粗糙,可有效减少电极间的色差,且能提高打线或焊线的附着力。     

Multi-view 3D display with high brightness based on a parallax barrier

A multi-view three-dimensional （3D） display provides a more realistic experience than a two-view 3D dis- play. Therefore, a multi-view 3D display with high brightness based on a parallax barrier is proposed. The parallax barrier in the 3D display has a gradient transmittance with enhanced frequency character- istic, which indicates that the aperture ratio of the parallax barrier can be increased, thereby improving brightness. Gradient transmittance is also helpful in reducing crosstalk. A prototype of the 3D display is developed. Experimental result shows that the 3D display has higher brightness than a conventional display. In addition, crosstalk is limited at a low level.     

Accurate measurement and influence on device reliability of defect density of a light-emitting diode

A method of accurately measuring the defect density of a high-power light-emitting diode （LED） is proposed. The method is based on measuring the number of emitting photons in the magnitude of 105 under the injection current as weak as nA and calculating the non-radiative recombination coefficient which is related to defect density. Defect density is obtained with the self-developed measurement system, and it is demonstrated that defect density has an important influence on LED optical properties like luminous flux and internal quantum efficiency （IQE）. At the same time, a batch of GaN-based LEDs with the chip size of 1 minx 1 mm are selected to conduct the accelerated aging tests lasting for 1000 hours. The results show that defect density exhibits a greater variation and is more sensitive to LED reliability than luminous flux during aging tests. Based on these results, it is concluded that for the GaN-based LED with a chip size of 1 mm ~ I mm, if its defect density is over 1017/cm3, the LED device performance suffers a serious deterioration, and finally fails.     

近紫外380nm发光二极管的量子阱结构优化

模拟分析了有源区不同垒层对380 nm近紫外发光二极管的内量子效率、电子空穴浓度分布、辐射复合效率等产生的影响。有源区垒层材料分别选用GaN、Al0.1Ga0.9N、Al0.1Ga0.9N/Al0.15Ga0.85N/Al0.1Ga0.9N,其中3层AlGaN的厚度比分别为6 nm/8 nm/6 nm和7 nm/6 nm/7 nm。对比分析发现,与GaN垒层相比,选用AlGaN系列垒层可以将更多的载流子限制在有源区内,空穴浓度可以提高近一个数量级,辐射复合效率可以提高2～10倍;3层AlGaN垒层相对于单一AlGaN垒层,载流子分布更加均匀,辐射复合效率可以提高7倍以上,内量子效率可以提高14.5%;采用不同厚度比的3层AlGaN垒层结构可以微调能带的倾斜程度,进一步减小极化效应。可以调节合适的厚度比减小极化效应对于载流子分布及内量子效率的影响。     

世界液晶电视市场和生产厂商

据市调公司NPD DisplaySearch3月的最新报告,世界液晶电视出货量2012年首次受创,当年只有第4季度微增0.6%,但仍不抵前3季度的萎靡,当年仍下滑1%,计2.03亿台。世界发达地区液晶电视出货量更惨跌18%,新兴市场虽有增长可也无法弥补这世界最大的消费市场。究其原因,首先无疑是受经济的困拢,其次是价格的影响,2012年世界平板的平均销售价仅下降了2%,相比于     

显示器的最佳亮度控制技术与低耗电化

1．前言薄型大画面液晶电视通过FHD化,实现宽屏幕化、高亮度化的不断进步。PC用液晶显示器方面也是如此,近年来通过高析像度化以及WIN—DOWSVISTA对应,正在从矩形向宽屏化变换。另外,装备有搭载HDMI端子以及对应元件信号的D—SUB端子的显示器也在增加,并实现了与各种AV装置、游戏装置的连接。     

各地政府加力推动半导体照明产业发展

半导体照明包括发光二极管（LED）和有机发光二极管（OLED）,亦称固态照明,是用第三代半导体材料制作的光源和显示器件,具有耗电量少、寿命长、无污染、色彩丰富、耐震动、可控性强等特点。     

索尼公司推出首款OLED专业现场制作监视器

索尼在NAB上展示了自己在专业监视器领域中的最先进技术成果——一款对于专业监视器来讲具有划时代意义的产品。新型的PVM-740是首款使用有机发光二极管（OLED）的现场制作监视器,它搭载有索尼特有的SuperTopEmission^TM技术,即使在有明亮的环境光条件下,也可有效地提供超一流的画面对比度和色彩。     

侧入式白色LED背光液晶暂时领先

当三星去年年初孤注一掷发布全系列LED（发光二极管）液晶电视时,不少人为之惊讶;半年后．当LED电视迅速在全球市场升温后．同行们又叹服三星先见之明的营销之道。LED液晶电视快速普及,三星功不可没,因为它直接提供了大幅降低LED电视成本的解决方案——白光侧入式LED电视。     

OLED——希望，神话及电视

在OLED产品被视为显示和照明市场的一个重要组成部分之前,仍有大量工作需要做。必要的成功因素包括建立在有竞争力的成本基础上的大规模生产．以及部分企业有追求新技术的意愿。不过,趋势还是积极的。OLED电视性能卓越而且省电,高效率、特有的波形因数和“柔和惬意”的色温也给OLED光源带来了新的机会。如果相关企业真能实现当初的规划,把技术实用化,我们将会在未来3年内看到OLED与TFT—LCD和LED光源之间的新竞争．