共查询到20条相似文献,搜索用时 15 毫秒
1.
提出了一种新型全方位反射铝镓铟磷(AlGaInP)薄膜发光二极管(LED)的结构和制作工艺,在这个结构里应用了低折射率的介质和高反射率的金属联合作为反光镜.用金锡合金(80Au20Sn,重量比)作为焊料把带有反光镜的AlGaInP LED外延片倒装键合到GaAs基板上(RS-LED),去掉外延片GaAs衬底,把被GaAS衬底吸收的光反射出去.通过与常规AlGaInP 吸收衬底LEDs(AS-LED)和带有DBR的AlGaInP 吸收衬底LEDs(AS-LED(DBR))电、光特性的比较,证明新型全方位反射AlGaInP薄膜LED结构能极大提高亮度和效率.正向电流20mA时,RS-LED的光输出功率和流明效率分别是AS-LED的3.2倍和2.2倍,是AS-LED(DBR)的2倍和1.5倍.RS-LED(20mA下峰值波长627nm)的轴向光强达到194.3mcd,是AS-LED(20mA下峰值波长624nm)轴向光强的2.8倍,是AS-LED(DBR)(20mA下峰值波长623nm)轴向光强的1.6倍.
关键词:
铝镓铟磷
薄膜发光管
全方位反射镜
发光强度 相似文献
2.
近年来,GaN基光子晶体发光二极管(light emitting diode,LED)的研究已经取得了一定的进展,利用光子晶体的光子带隙效应和光栅衍射原理,在LED上制作光子晶体结构将会提高出光效率.本文为了提高AlGaInP系LED的光提取效率,分析了常规LED光提取效率受到限制的原因,将光子晶体结构引入了AlGaInP系LED的器件结构设计,通过理论分析与实验验证,结果显示:光子晶体结构对于提高AlGaInP系LED的光提取效率同样起到了明显的效果,引入光子晶体后,LED的输出光强比常规结构LED平均
关键词:
AlGaInP系LED
光子晶体
光提取效率
光强 相似文献
3.
4.
5.
6.
为降低ITO薄膜对紫外波段的光吸收,制备低电压高功率的紫外LED,研究了一种基于金属掺杂ITO透明导电层的365 nm紫外LED的制备工艺。利用1 cm厚的石英片生长了不同厚度ITO薄膜以及在ITO上掺杂不同金属的新型薄膜,并研究了在不同的退火条件下这种薄膜的电阻和透过率,分析了掺杂金属ITO薄膜的带隙变化。将这种掺杂的ITO薄膜生长在365 nm外延片上并完成电极生长,制备成14 mil×28 mil的正装LED芯片。利用电致发光(EL)设备对LED光电性能进行测试并对比。实验结果表明:掺Al金属的ITO薄膜能够相对ITO薄膜的带隙提高0.15 eV。在600℃退火后,方块电阻降低6.2 Ω/□,透过率在356 nm处达到90.8%。在120 mA注入电流下,365 nm LED的电压降低0.3 V,功率提高14.7%。ITO薄膜掺金属能够影响薄膜带隙,改变紫光LED光电性能。 相似文献
7.
采用磁控溅射制备GZO和具有ITO界面调控层的GZO(ITO/GZO)透明导电薄膜作为大功率LED的电流扩散层,对比研究界面调控层对LED器件性能的影响。研究结果表明,ITO/GZO薄膜的透过率在可见光区达80%以上,退火后的ITO/GZO薄膜有较低的电阻率(1.15×10-3 Ω·cm)。ITO调控层的介入能够调制GZO表面粗糙度,有利于改善LED外量子效率,降低GZO/p-GaN界面的接触势垒,提高LED器件的光电性 能。通过ITO界面调控后,LED器件20 mA驱动电流下的工作电压从9.5 V降低为6.8 V,发光强度从245 mcd 升到297 mcd,提高了20%;驱动电流为35 mA时,其发光强度从340.5 mcd 升到511 mcd,提高了50%。 相似文献
8.
Fabrication and characterization of Pt intermediate transparent and conducting ITO/Pt/ITO multilayer films 总被引:1,自引:0,他引:1
J.I. Choi 《Journal of Physics and Chemistry of Solids》2009,70(2):272-1933
Platinum intermediate transparent and conducting ITO/metal/ITO (IMI) multilayered films were deposited by RF and DC magnetron sputtering on polycarbonate substrates without intentional substrate heating. Changes in the microstructure and optoelectrical properties of the films were investigated with respect to the thickness of the intermediate Pt layer in the IMI films. The thickness of Pt film was varied from 5 to 20 nm.In XRD measurements, neither ITO single-layer films nor IMI multilayer films showed any characteristic diffraction peaks for In2O3 or SnO2. Only a weak diffraction peak for Pt (1 1 1) was obtained in the XRD spectra. Thus, it can be concluded that the Pt-intermediated films in the IMI films did not affect the crystallinity of the ITO films. However, equivalent resistivity was dependent on the presence and thickness of the Pt-intermediated layer. It decreased as low as 3.3×10−4 Ω cm for ITO 50 nm/Pt 20 nm/ITO 30 nm films. Optical transmittance was also strongly influenced by the Pt-intermediated layer. As Pt thickness in the IMI films increased, optical transmittance decreased to as low as 30% for ITO 50 nm/Pt 20 nm/ITO 30 nm films. 相似文献
9.
双条形电极结构AlGaInP-LED微阵列器件的设计和实验研究 总被引:1,自引:1,他引:0
设计了一种基于AlGaInP发光材料的像素为320×240、单元像素面积为100 μm×100 μm 微型LED阵列。通过仿真和分析,设计了一种双条形电极结构。考虑到不同电极宽度下的电流分布情况以及电极的遮光效应,设计了电极宽度为13 μm 的优化电极结构,使得每个发光像素的表面出光面积比为50.15%,并分析了电极对有源层出射的光的反射影响。制定了基于MOEMS工艺的微型LED器件的制作流程并进行了基本实验研究,最终给出了制作出的上电极的单个单元照片。 相似文献
10.
Review of flexible and transparent thin-film transistors based on zinc oxide and related materials 下载免费PDF全文
Flexible and transparent electronics enters into a new era of electronic technologies.Ubiquitous applications involve wearable electronics,biosensors,flexible transparent displays,radio-frequency identifications(RFIDs),etc.Zinc oxide(ZnO) and relevant materials are the most commonly used inorganic semiconductors in flexible and transparent devices,owing to their high electrical performances,together with low processing temperatures and good optical transparencies.In this paper,we review recent advances in flexible and transparent thin-film transistors(TFTs) based on ZnO and relevant materials.After a brief introduction,the main progress of the preparation of each component(substrate,electrodes,channel and dielectrics) is summarized and discussed.Then,the effect of mechanical bending on electrical performance is highlighted.Finally,we suggest the challenges and opportunities in future investigations. 相似文献
11.
12.
13.
Indium tin oxide (ITO) thin film is one of the most widely used as transparent conductive electrodes in all forms of flat panel display (FPD) and microelectronic devices. Suspension of already crystalline conductive ITO nanoparticles fully dispersed in alcohol was spun, after modifying with coupling agent, on glass substrates. The low cost, simple and versatile traditional photolithography process without complication of the photoresist layer was used for patterning ITO films. Using of UV light irradiation through mask and direct UV laser beam writing resulted in an accurate linear, sharp edge and very smooth patterns. Irradiated ITO film showed a high transparency (∼85%) in the visible region. The electrical sheet resistance decrease with increasing time of exposure to UV light and UV laser. Only 5 min UV light irradiation is enough to decrease the electrical sheet resistance down to 5 kΩ□. 相似文献
14.
Facile patterning of electrodes is required for various electronic applications, particularly in solution-processed oxide thin-film transistors (TFTs). In this study, source and drain electrodes were prepared from silver nanowires (AgNWs) using spray-coating and hot press techniques. Although spray coating allowed production of AgNW patterns, which could function as electrodes in oxide TFT, the as-sprayed films did not provide a sufficient physical contact with oxide semiconductors and formed interspaces that impeded electron injection. At the same time, hot press technique produced denser AgNW networks that had a tight contact with the oxide semiconductors. As a result, hot-pressed films were considered as satisfactory source and drain electrodes for high-performance oxide TFTs, as they provided an easy electron injection. Finally, the prepared oxide TFTs with hot-pressed AgNW electrodes exhibited average field-effect mobility of 4.75 ± 1.5 cm2/V, significantly higher than that of the TFTs with as-sprayed AgNW electrodes (0.08 ± 0.05 cm2/V). 相似文献
15.
市场上的节能台灯普遍存在光效低、亮度不均匀、眩光较严重的缺点,以改善这些缺点作为出发点,设计了一款高均匀低眩光的LED护眼台灯.设计加入非球面反光杯灯罩来收集LED光源发出的大角度光线,提高了光能的利用率并改善了眩光.加入配光透镜消除接受平面存在的中心亮斑,解决了均匀照明问题.通过ProE三维设计软件进行实体建模,导入TracePro进行光线模拟和仿真分析,结果表明这一LED台灯配光设计可在工作距离为450 mm、直径为700 mm的接收面内实现低眩光高均匀照明,平均照度可达497.1 lx,平均度达到0.9左右.这一高均匀低眩光LED护眼台灯的设计方案有着广阔的实际应用前景. 相似文献
16.
本文提出在Kα波段圆柱过模结构绕射辐射器件(RDG)中引入一种带有锥度结构的同轴内开槽布拉格反射器.采用复功率守恒技术(CCPT)对该反射器的频率响应特性进行分析.研究了相位匹配段长度,波纹槽深及锥度对反射器频率响应特性的影响,分析了波纹初始相位对反射器选模特性的影响,发现该反射器具有良好的模式选择特性.本文的研究工作为同轴Bragg反射器结构的研究提供了重要的理论分析手段.
关键词:
同轴Bragg反射器
频率响应特性
复功率守恒
绕射辐射振荡器 相似文献
17.
18.
Characteristics of pentacene organic thin film transistor with top gate and bottom contact 下载免费PDF全文
High performance pentacene organic thin film transistors (OTFT) were
designed and fabricated using SiO2 deposited by electron beam
evaporation as gate dielectric material. Pentacene thin films were
prepared on glass substrate with S--D electrode pattern made from ITO
by means of thermal evaporation through self-organized process. The
threshold voltage VTH was --2.75± 0.1V in 0---50V
range, and that subthreshold slopes were 0.42± 0.05V/dec. The
field-effect mobility (μEF) of OTFT device increased with
the increase of VDS, but the μEF of OTFT device
increased and then decreased with increased VGS when VDS was kept constant. When VDS was --50V, on/off current
ratio was 0.48× 105 and subthreshold slope was 0.44V/dec.
The μEF was 1.10cm2/(V.s), threshold voltage
was --2.71V for the OTFT device. 相似文献
19.
A.A. Dakhel 《Current Applied Physics》2012,12(1):1-6
Thin films of boron and hydrogen-codoped CdO (B&H-codoped CdO) oxide with different boron content have been prepared on glass and silicon substrates. The effects of codoping on the structural, electrical, and optical properties of the host CdO films were systematically studied. The structural study shows that doped boron ions occupied locations in interstitial positions and/or Cd2+-ion vacancies of CdO lattice. The bandgap of B-doped CdO shrinks by 25-38% compare to hydrogenated CdO. Such bandgap narrowing was phenomenological studied in the framework of the available models. The electrical behaviours show that all the prepared B&H-doped CdO films are degenerate semiconductors. However, the hydrogenated 7.9% boron doped CdO has resistivity of 1.52 × 10−4 Ω cm, mobility of 47.5 cm2/V s, and carrier concentration of 8.6 × 1020 cm−3. The optoelectronic measurements in visible and NIR spectral range demonstrate the utility of the oxide/p-Si heterojunction in photodetection applications. 相似文献
20.
F. Zhou H.P. LinL. Zhang J. LiX.W. Zhang D.B. YuX.Y. Jiang Z.L. Zhang 《Current Applied Physics》2012,12(1):228-232
In this paper, top-gate thin-film transistors (TFTs) using amorphous In-Ga-Zn-O as the n-channel active layer and SiO2 as gate insulator were fabricated by radio frequency magnetron sputtering at room temperature. In this device, a SiO layer was used to be a buffer layer between active layer and gate insulator for preventing the damage of the InGaZnO surface by the process of sputtering SiO2 with relatively high sputtering power. The thickness of buffer layers was studied and optimized for enhancing the TFTs performances. Contrasting to the TFTs without buffer layer, the optimized thickness of 10 nm SiO buffer layer improved the top-gate TFTs performances greatly: mobility increases 30%, reached 1.29 cm2/V s, the Ion/Ioff ratio increases 3 orders, and the trap density at the interface of channel/insulator decreases about 1 order, indicated that the improvement of semiconductor/dielectric interface by buffering the sputtering power. 相似文献