共查询到19条相似文献,搜索用时 125 毫秒
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采用相同生长结构的MOCVD外延片,研究制备适用于单片集成的垂直腔面发射与接收器件及列阵,发射及接收波长相同,由谐振腔模式决定.采用双氧化电流限制结构,优化串联电阻,提高电光转换效率,制备980nm波段发光器件及1×16列阵芯片,发射谱线半宽≤4.8nm,注入电流为50mA时,发射功率为0.7mW.对列阵芯片用探针进行在线检测,器件均有良好的发光特性.接收器件光电响应具有良好的波长和空间选择特性,谐振接收波长可利用不同角度光入射实现简单易行的调节.通过腐蚀器件顶部DBR的方法调节入射镜反射率,可以分别实现具有单片集成结构的谐振增强型发射和接收器件的优化设计. 相似文献
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通信感知一体化是6G关键技术之一。氮化镓量子阱二极管的发射光谱和光探测谱存在重叠区,量子阱二极管光探测器能够吸收具有相同量子阱结构的光发射器件发出的短波长光子,生成光电流。该文基于该物理现象,研制同质集成光发射光接收器件的氮化镓光电子芯片,由于单个量子阱二极管芯片器件自身发光干扰导致感知外界光信号弱,但是收发分离芯片又存在效率低、紧凑性弱、鲁棒性差等问题,将具有相同量子阱结构的量子阱二极管器件制备在同一块芯片上,分别作为发光和接收器件,构建自由空间逆向光通信系统,探索可见光通信感知一体化芯片及关键技术。 相似文献
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微腔结构顶发射有机白光器件 总被引:2,自引:1,他引:1
结合微腔效应,通过调节不同发光层的厚度制作了顶发射有机白光器件.器件结构为Si/Ag/Ag2O/m-MTDATA/NPB/DPVBi/DCJTB:Alq3/Alq3/LiF/Al/Ag,其中DPVBi,DCJTB与Alq3的掺杂层分别作为蓝光和红光发光层,在选定490 nm的谐振波长时,通过调节DPVBi和掺杂层的厚度来实现对器件发光色度的调节.当DPVBi厚度为1 nm,电压为9 V时,器件的色坐标为(0.33,0.34),非常接近白光等能点.此项工作为利用微腔效应制作高效率高亮度顶发射白光器件奠定了基础. 相似文献
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980 nm高峰值功率微型化VCSEL脉冲激光光源 总被引:1,自引:1,他引:0
报道了输出波长980 nm的高峰值功率垂直腔面发射激光器(VCSEL)及其微型化脉冲激光光源.通过优化VCSEL单元器件的结构,有效抑制了宽面VCSEL结构中的非均匀电流分布,提高了单元器件的斜率效率,获得了直径400μm,峰值输出功率62 W的VCSEL单元器件;在此基础上,研制出由单元器件组合封装而成的VCSEL"准列阵"子模块以及集成驱动电路的微型化VCSEL脉冲激光光源,该光源在脉冲驱动条件为30 ns、2 k Hz、105 A条件下的峰值输出功率达到226 W,光脉冲宽度35 ns,中心波长979.4nm,斜率效率达到2.15 W/A. 相似文献
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(上接第4期)
2.3高速、可调波长和单片集成式光发射芯片(EAML-SOA)
对于40G TWDM-PON发射端来说,首先要解决宽带光芯片问题.为了缩小体积,提高光电性能,国内外正在研发宽带单片集成芯片.这种芯片性能优越,可充分满足40G TWDM-PON发射端技术要求,具有多种可能结构形式.其中,基于电控技术、波长可调谐的光发射芯片EAML-SOA,性能优越,商用化程度较高,EAML-SOA把具有MQW-LD、相移(DBR)、电吸收调制(EAM)、半导体光放大(SOA)单片集成在InP基片上,其芯片结构示意图如图5所示. 相似文献
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Taylor D.M. Bennett C.R. Shepherd T.J. Michaille L.F. Nielsen M.D. Simonsen H.R. 《Electronics letters》2006,42(6):331-332
A novel microstructured fibre has been created for use in an optical interconnection system. The fibre has low crosstalk with a high density of cores corresponding to 1150 channels/mm/sup 2/. A repeating pseudorandom binary sequence has been used to demonstrate a four-channel transmit/receive system using vertical cavity surface emitting lasers as both emitters and detectors. 相似文献
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R. M. Fletcher C. P. Kuo T. D. Osentowski K. H. Huang M. G. Craford V. M. Robbins 《Journal of Electronic Materials》1991,20(12):1125-1130
The growth and properties of high performance surface light emitting diodes which utilize a GaP window layer are presented.
The devices consist of an AlGaInP double heterostructure lattice matched to a GaAs substrate. A lattice mismatched GaP layer
is then grown on top of the heterostructure. The resulting upper confining and window layers have high electrical conductivity
and optical transmissivity allowing for the fabrication of red-orange and yellow emitters with performance superior to existing
commercial technologies. The effect of different confining and window layer structures on device performance is described,
including characteristics of the shortest wavelength AlGaInP green emitters yet reported. 相似文献
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Although both high-index substrates and horizontal-dipole emitters have been shown to be facile approaches for enhancing OLED (organic light emitting diode) light extraction, the full benefits and potential of their combination for OLED optical out-coupling have not been thoroughly studied and explored. Simulation studies indicate that very high optical coupling efficiency into substrates ϕsub (and perhaps similarly high OLED external quantum efficiencies) of ~90% can be possibly obtained with both high-index substrates (refractive index >1.8–1.9) and highly horizontal-dipole emitters (horizontal dipole ratio >85%), together with adoption of low-index or index-matching carrier transport layers and optimization of organic layer and transparent electrode thicknesses. With these judicious device design conditions, all waveguided modes and surface plasmon modes in devices can be effectively suppressed for optimal optical out-coupling. Finally, combining the sapphire substrate having high index of n~1.78, the recently developed OLED emitters having high horizontal emitting dipole ratio of up to 87%, and simple external extraction lens, OLED devices having external quantum efficiency of over 80% was successfully realized. 相似文献
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Selahattin Sayil 《Analog Integrated Circuits and Signal Processing》2008,56(3):213-221
A silicon p–n junction that is biased in avalanche breakdown mode emits visible light. Although the efficiency of such silicon
emitters is poor, their ability to modulate at GHz frequencies make them a good choice for many applications including optical
interconnect and optical contactless logic testing. Results demonstrate the feasibility of an all silicon optical interconnect
system and an all silicon contactless testing methodology using the silicon light emitter and standard silicon detectors.
The development of truly efficient silicon light emitting would enable many new applications. 相似文献
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Full‐Color Delayed Fluorescence Materials Based on Wedge‐Shaped Phthalonitriles and Dicyanopyrazines: Systematic Design,Tunable Photophysical Properties,and OLED Performance
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In Seob Park Sae Youn Lee Chihaya Adachi Takuma Yasuda 《Advanced functional materials》2016,26(11):1813-1821
Purely organic light‐emitting materials, which can harvest both singlet and triplet excited states to offer high electron‐to‐photon conversion efficiencies, are essential for the realization of high‐performance organic light‐emitting diodes (OLEDs) without using precious metal elements. Donor–acceptor architectures with an intramolecular charge‐transfer excited state have been proved to be a promising system for achieving these requirements through a mechanism of thermally activated delayed fluorescence (TADF). Here, luminescent wedge‐shaped molecules, which comprise a central phthalonitrile or 2,3‐dicyanopyrazine acceptor core coupled with various donor units, are reported as TADF emitters. This set of materials allows systematic fine‐tuning of the band gap and exhibits TADF emissions that cover the entire visible range from blue to red. Full‐color TADF‐OLEDs with high maximum external electroluminescence quantum efficiencies of up to 18.9% have been demonstrated by using these phthalonitrile and 2,3‐dicyanopyrazine‐based TADF emitters. 相似文献
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《Electron Devices, IEEE Transactions on》1979,26(8):1230-1238
The performance of state-of-the-art double-heterojunction (DH) surface and edge emitters are compared with respect to their use in high-data-rate fiber-optical communication systems. Thick-window (20-25-µm) surface emitters with 2-2.5-µm thick active layers and emitting up to 15-mW optical power at 300 mA have been fabricated. For edge emitters, we use very-high-radiance-type devices with ≃ 500-Å thick active layers. For these two types of LED's we examine differences in structure and light coupling efficiency to fibers of various numerical apertures (NA). For typically good devices we compare the diodes' output power capabilities, the powers coupled into step- and graded-index fibers of various NA, and their respective frequency response. For the same drive current level, we find that edge emitters couple more power than surface emitters into fibers with NAlsim 0.3 . The edge emitters also have ≈ 5 times larger bandwidths. We estimate that an edge emitter can couple 5-6 times more power into low numerical aperture (NAlsim 0.2 ) fibers than a surface emitter of the same bandwidth. We conclude that edge emitters are preferred to surface emitters for optical data rates above 20 Mbits/s. 相似文献
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Achieving Above 60% External Quantum Efficiency in Organic Light‐Emitting Devices Using ITO‐Free Low‐Index Transparent Electrode and Emitters with Preferential Horizontal Emitting Dipoles
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Chun‐Yang Lu Min Jiao Wei‐Kai Lee Chien‐Yu Chen Wei‐Lung Tsai Chun‐Yu Lin Chung‐Chih Wu 《Advanced functional materials》2016,26(19):3250-3258
Comprehensive theoretical and experimental studies are reported on organic light‐emitting devices (OLEDs) adopting either the conventional high‐index indium tin oxide (ITO) electrode or the low‐index conducting polymer electrode, either isotropic emitters or emitters having preferentially horizontal emitting dipoles, and different layer structures. Intriguingly, with the use of low‐index electrode in the device, in addition to the known suppression of waveguided modes, the surface plasmon modes can also be effectively suppressed with larger emitter‐to‐metal distances yet with better immunity to accompanied increase of the competing waveguided modes (induced by thicker organic layers) as in the ITO device. As a result, overall coupling efficiencies of OLED internal radiation into substrates can be significantly enhanced over those with ITO electrodes. Through effective extraction of radiation within substrates, green phosphorescent OLEDs adopting both the low‐index ITO‐free electrode and the preferentially horizontal dipole emitter (with a horizontal dipole ratio of 76%) achieve a high external quantum efficiency (EQE) of up to ≈64%. The simulation also predicts that very high EQEs of ≥80% are possible with highly horizontal dipole emitters for all red/green/blue/white OLEDs, clearly revealing the potential of combining low‐index transparent electrodes and horizontal dipole emitters for high‐efficiency OLEDs. 相似文献
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Yi‐Lu Chang Brett A. Kamino Zhibin Wang Michael G. Helander Yingli Rao Lily Chai Suning Wang Timothy P. Bender Zheng‐Hong Lu 《Advanced functional materials》2013,23(25):3204-3211
Phosphorescent organic light emitting diodes (PHOLEDs) have undergone tremendous growth over the past two decades. Indeed, they are already prevalent in the form of mobile displays, and are expected to be used in large‐area flat panels recently. To become a viable technology for next generation solid‐state light source however, PHOLEDs face the challenge of achieving concurrently a high color rendering index (CRI) and a high efficiency at high luminance. To improve the CRI of a standard three color white PHOLED, one can use a greenish‐yellow emitter to replace the green emitter such that the gap in emission wavelength between standard green and red emitters is eliminated. However, there are relatively few studies on greenish‐yellow emitters for PHOLEDs, and as a result, the performance of greenish‐yellow PHOLEDs is significantly inferior to those emitting in the three primary colors, which are driven strongly by the display industry. Herein, a newly synthesized greenish‐yellow emitter is synthesized and a novel device concept is introduced featuring interzone exciton transfer to considerably enhance the device efficiency. In particular, high external quantum efficiencies (current efficiencies) of 21.5% (77.4 cd/A) and 20.2% (72.8 cd/A) at a luminance of 1000 cd/m2 and 5000 cd/m2, respectively, have been achieved. These efficiencies are the highest reported to date for greenish‐yellow emitting PHOLEDs. A model for this unique design is also proposed. This design could potentially be applied to enhance the efficiency of even longer wavelength yellow and red emitters, thereby paving the way for a new avenue of tandem white PHOLEDs for solid‐state lighting. 相似文献
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Due to their long lifetime and high efficacy, light emitting diodes have the potential to revolutionize the illumination industry. However, self heat and high environmental temperature which will lead to increased junction temperature and degradation due to electrical overstress can shorten the life of the light emitting diode. In this research, a methodology to investigate the degradation of the LED emitter has been proposed. The epoxy lens of the emitter can be modelled using simplified Eyring methods whereas an equation has been proposed for describing the degradation of the LED emitters. 相似文献