共查询到18条相似文献,搜索用时 62 毫秒
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InGaN/GaN MQW双波长LED的MOCVD生长 总被引:1,自引:0,他引:1
利用金属有机物化学气相淀积(MOCVD)系统生长了InGaN/GaN多量子阱双波长发光二极管(LED).发现在20 mA正向注入电流下空穴很难输运过蓝光和绿光量子阱间的垒层,这是混合量子阱有源区获得双波长发光的主要障碍.通过掺入一定量的In来降低蓝光和绿光量子阱之间的垒层的势垒高度,增加注入到离p-GaN层较远的绿光有源区的空穴浓度,从而改变蓝光和绿光发光峰的强度比.研究了蓝光和绿光量子阱间垒层In组分对双波长LED的发光性质的影响.此外,研究了双波长LED发光特性随注入电流的变化. 相似文献
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二维范德华材料凭借其优异的光学和电学特性,自被发现以来一直作为延续集成电路摩尔定律的重要基础电子材料而备受关注.通过机械剥离的方法得到高质量的二维材料进行实验室层面的研究工作已经不能满足现阶段的需要.采用金属有机化学气相沉积(MOCVD)技术可以得到高质量的大面积二维范德华材料,并具有生长层数和成核密度可控的优势.以过渡金属硫化物(TMDC)为例,分别从生长条件、金属有机源材料、衬底、催化剂等方面综述了采用MOCVD技术生长二维范德华材料的研究进展,同时讨论了二维材料的范德华异质结构的特性及应用.利用MOCVD技术优势可以推动二维范德华材料的大规模应用.最后总结了 MOCVD法生长二维范德华材料现阶段的优势与不足,并对其未来的发展进行了展望. 相似文献
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短波长谐振腔发光二极管外延及性能研究 总被引:1,自引:1,他引:0
利用金属有机化学气相沉积(MOCVD)方法生长650 nm谐振腔半导体发光二极管(RCLED),利用光致发光(PL)谱和电致发光(EL)谱研究了其发光特性.由于上、下布拉格反射镜的影响,导致其PL强度只有普通LED的1/20;EL谱纯度有了很大提高,半峰宽(FWHM)由普通LED的20 nm降到4 nm以下.最好的器件测试结果表明,可以在60 mA、2.71 V下,实现1.45 mW以上发射功率,最窄FWHM在3 nm. 相似文献
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采用金属有机物化学气相淀积(MOCVD)方法设计并生长了应变多量子阱InGaAs/AlGaAs,并且对其进行了光致发光(PL)谱、双晶X射线衍射(DXRD)谱和电化学C-V等的测试。然后以InGaAs/AlGaAs作为有源层,以GaAs衬底作为透明衬底,p面金属电极AuBe合金作为镜面反射层,采用倒装技术制备了近红外发光二极管(LED)。在输入电流为20mA下的正向电压为1.2V左右,电致发光谱的峰值波长为938nm,10μA下的反向击穿电压为5-6V,在输入电流为50mA下得出输出功率3.5mW,对应电压为1.3V,在输入电流为300mA时得到最大输出功率为12mW。 相似文献
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设计并研制了用于光电集成(OEIC)的InP基异质结双极晶体管(HBT),介绍了工艺流程及器件结构。分别采用金属有机化学气相沉积(MOCVD)及分子束外延(MBE)生长的外延片,并在外延结构、工艺流程相同的条件下,对两种生长机制的HBT直流及高频参数进行和分析。结果表明,采用MOCVD生长的InP基HBT,直流增益为30倍,截止频率约为38GHz;MBE生长的HBT,直流增益达到100倍,截止频率约为40GHz。这表明,MBE生长的HBT外延层质量更高,在相同光刻条件下,所对应的HBT器件的性能更好。 相似文献
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Wonseok Lee Jae Limb Jae-Hyun Ryou Dongwon Yoo Theodore Chung Russell D. Dupuis 《Journal of Electronic Materials》2006,35(4):587-591
We investigated the electrical and structural qualities of Mg-doped p-type GaN layers grown under different growth conditions
by metalorganic chemical vapor deposition (MOCVD). Lower 300 K free-hole concentrations and rough surfaces were observed by
reducing the growth temperature from 1,040°C to 930°C. The hole concentration, mobility, and electrical resistivity were improved
slightly for Mg-doped GaN layers grown at 930°C with a lower growth rate, and also an improved surface morphology was observed.
In0.25Ga0.75N/GaN multiple-quantum-well light emitting diodes (LEDs) with p-GaN layers grown under different conditions were also studied.
It was found from photoluminescence studies that the optical and structural properties of the multiple quantum wells in the
LED structure were improved by reducing the growth temperature of the p-layer due to a reduced detrimental thermal annealing
effect of the active region during the GaN:Mg p-layer growth. No significant difference in the photoluminescence intensity
depending on the growth time of the p-GaN layer was observed. However, it was also found that the electroluminescence (EL)
intensity was higher for LEDs having p-GaN layers with a lower growth rate. Further improvement of the p-GaN layer crystalline
and structural quality may be required for the optimization of the EL properties of long-wavelength (∼540 nm) green LEDs. 相似文献
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The growth of epitaxial films on featured substrates has an important device application in junction-confinement, double hetero-structure
light emitting diodes. These devices are presently grown by a liquid phase epitaxy process but growth by metalorganic chemical
vapor deposition is desirable because of MOCVD's superior surface quality, uniformity, and throughput. This paper describes
the effect of growth parameters on AlGaAs films deposited by atmospheric-pressure MOCVD into substrate holes typically made
in the fabrication of junction-confinement LEDs. MOCVD growth replicates the substrate features; it does not give a planar
surface over the holes. The behavior of epitaxy filling into holes is strongly dependent on growth temperature and total gas
flow and largely independent of substrate misorientation and the thickness of the layer grown. Wet-etched holes formed (ll0)-oriented
V-groove and dovetail-groove features on the hole circumference. Faceting of the MOCVD growth was seen on the wall with the
(111)A feature while smooth growth was seen on the etched (111)B surface.
Deceased. 相似文献
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F. M. Steranka D. C. Defevere Camras M.D. S. L. Rudaz D. K. Mc Elfresh L. W. Cook W. L. Snyder M. G. Craford 《Journal of Electronic Materials》1995,24(10):1407-1412
Electroluminescent decay and internal quantum efficiency measurements are made as a function of temperature on two double
heterostructure AIGaAs light emitting diodes (LEDs) that emit in the visible (red) portion of the spectrum. The electroluminescent
lifetimes increase by more than a factor of ten and the internal quantum efficiency falls by a factor of three as the temperature
is raised from 90 to 400K. By analyzing the data with a model that accounts for the transfer with increasing temperature of
the minority-carrier electrons from the direct-gap to the indirect-gap minima in the p-type active layer of these near-crossover
LEDs, values for the radiative and nonradiative lifetimes as a function of temperature are obtained. A fit to the radiative-lifetime
data results in an estimate of 1.3 × 10−10 cm3s−1 for the room-temperature radiative recombination coefficient of Al0.39Ga0.61As, which is very similar to values reported for GaAs. The nonradiative lifetimes are found to be nearly independent of temperature
from 220 to 400K and provide upper limits of 940 and 1250 cms−1 for the interface recombination velocities of the two samples. These values are roughly an order of magnitude lower than
any previously reported values for high-Al-content (x > 0.3) AlxGa1−xAs heterostructures. 相似文献
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隧道带间级联双波长可见光半导体激光器制备 总被引:3,自引:2,他引:1
利用金属有机物化学汽相淀积(MOCVD)一次外延生长了含有2个有源区的隧道带间级联双波长可见光半导体激光器(LD)材料。其隧道结为GaAs。2个有源区分别为AlGaAs单量子阱和GaInP多量子阱。SEM照片表明,材料生长质量良好。用生长的材料制备了双沟深腐蚀结构F P腔激光器。器件的阈值电流为177mA,未镀膜时的单面斜率效率为1.3W/A,远场为单瓣,垂直和水平方向的发散角分别为8°和34°。在输出光功率为100mW时,2个激射波长分别为699nm和795nm,与PL测试结果相一致。 相似文献
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基于BAlq的有机电致发光器件的磁效应 总被引:2,自引:1,他引:1
研究了ITO/NPB(40nm)/BAlq(60nm)/BCP(5nm)/LiF(0.8nm)/AI有机电致发光器件(OLED)的磁效应.实验结果表明,磁场在10mT时,器件的效率最大增加了34%,这一结果是由于三线态激子与三线态激子间的相互淬灭产生激发单线态激子从而使单线态激子比率增加,致使电致发光(EL)增强.当磁... 相似文献
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Ching-Long Jiang Mark Mashas Maria Ferreira John Kulick Eugene Imhoff William Reysen 《Journal of Electronic Materials》1995,24(11):1621-1624
Selective regrowth of indium phosphide (InP) using organometallic vapor phase epitaxy (OMVPE) on a circular shaped mesa has
been demonstrated for the first time. Inclusion of an interfacial layer of indium gallium arsenide phosphide between the circular
dielectric mask and the underlying material produces a favorable smooth mesa profile by controlling the level of undercut
during mesa etching. This combination of profile and undercut was found to be critical for successful selective regrowth and
planarization. To the best of our knowledge, this is the first time that a surface light emitting diode has been demonstrated
with a selective OMVPE semi-insulating regrowth. The semi-insulating InP layer reduces parasitic capacitance and improves
the heat dissipation out of the device. These salient features make these devices suitable for high speed digital and analog
communication applications. 相似文献
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Jaeheung Ha Subeom Park Donghyun Kim Jaechul Ryu Changhee Lee Byung Hee Hong Yongtaek Hong 《Organic Electronics》2013,14(9):2324-2330
Recently, graphene-based organic light emitting diodes (OLEDs) were successfully demonstrated using graphene as anodes. However, the graphene electrodes have not been utilized for polymer light emitting diodes (PLEDs) yet, although the simpler device structure and the solution-based fabrication process of PLEDs are expected to be more advantageous in terms of time and cost. Here we demonstrate high-performance polymer light emitting diodes (PLEDs) with simple two-layer structures using interface-engineered single-layer graphene films as anodes. The single-layer graphene synthesized by chemical vapor deposition methods was transferred onto a glass substrate utilizing an elastic stamp, and its work function was engineered by varying the duration and the power of ultraviolet ozone (UVO) treatment. Thus, we were able to optimize the contact between silver electrodes and the graphene anodes, leading to the considerable enhancement of light-emitting performance. 相似文献