共查询到12条相似文献,搜索用时 46 毫秒
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面对即将来临的半导体固态照明(SSL)技术革命,蓝、绿光LED芯片技术在过去关键的20年中所走过的历程是值得认真回顾的。文章简要介绍了SSL技术的材料物理基础以及器件的基本光电参数特征,在此基础上回顾了该技术发展历程的关键节点。针对该技术核心应用领域——固态节能照明发展的需要,对未来技术发展趋势也做了展望。 相似文献
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The objective of this work is to simulate a single quantum well ultraviolet light emitting diode (LED) based on AlGaN/GaN/AlGaN and AlGaN/BGaN/AlGaN, by using TCAD Silvaco simulator. The first structure has a GaN quantum well taken between two layers, of n-AlGaN and p-AlGaN. The second one has a BGaN quantum well instead of GaN. We fix the concentration of the boron in BGaN to only 1% and we vary the thickness of GaN and BGaN quantum well layer from 7 to 20 nm, for the two structures. As results, we obtain respectively for GaN-LED and BGaN-LED, a maximum current of 0.52 and 0.27 mA, a maximum power spectral density of 1.935 and 6.7 W cm−1 eV−1, a maximum spontaneous emission of 3.34 × 1028 and 3.43 × 1028 s−1 cm−3 eV−1, and a maximum Light output power of 0.56 and 0.89 mW. 相似文献
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设计了方形和阶梯状两大类的图形化蓝宝石衬底(PSS), 使用Crosslight公司的工艺软件CSuprem建立了三维的方形和阶梯状两类图形衬底GaN LED器件, 然后使用APSYS软件模拟计算出它们的光电特性。并且对方形图形衬底的刻蚀深度进行了优化, 通过对模拟结果的比较得到刻蚀深度与边长的比值为0.4时, 这种方形图形衬底GaN LED的光提取效率最高, 且比平面衬底提高了20.13%。对阶梯状图形衬底的阶梯层数进行了比较, 发现随着阶梯层数的增加, 光提取效率也随着增加, 阶梯状层数为5时, 光提取效率比平面衬底提高了30.03%。并对方形PSS LED进行了实验验证。 相似文献
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GaN基蓝光器件的研究进展 总被引:1,自引:0,他引:1
本文对近几年GaN基蓝光器件,包括GaN基发光二极管和激光二极管的发展历程进行了全面介绍和评价。指出GaN基蓝光LED的研究开发技术将在1-2年内走向成熟,从而实现大规模商业化生产,而GaN基蓝光LD也将在近二年内实用化。 相似文献
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The practical design of GaN-based Schottky barrier diodes(SBDs) incorporating a field plate(FP) structure necessitates an understanding of their working mechanism and optimization criteria.In this work,the influences of the parameters of FPs upon breakdown of the diode are investigated in detail and the design rules of FP structures for GaN-based SBDs are presented for a wide scale of material and device parameters.By comparing three representative dielectric materials(SiO2,Si3N4 and Al2O3) selected for fabricating FPs,it is found that the product of dielectric permittivity and critical field strength of a dielectric material could be used as an index to predict its potential performance for FP applications. 相似文献
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The typical light emission efficiency behaviors of InGaN/GaN multi-quantum well (MQW) blue light- emitting diodes (LEDs) grown on c-plane sapphire substrates are characterized by pulsed current operation mode in the temperature range 40 to 300 K. At temperatures lower than 80 K, the emission efficiency of the LEDs decreases approximately as an inverse square root relationship with drive current. We use an electron leakage model to explain such efficiency droop behavior; that is, the excess electron leakage into the p-side of the LEDs under high forward bias will significantly reduce the injection possibility of holes into the active layer, which in turn leads to a rapid reduction in the radiative recombination efficiency in the MQWs. Combining the electron leakage model and the quasi-neutrality principle in the p-type region, we can readily derive the inverse square root dependent function between the light emission efficiency and the drive current. It appears that the excess electron leakage into the p-type side of the LEDs is primarily responsible for the low-temperature efficiency droop behavior. 相似文献
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Hwan Hee Jeong Kwang Ki ChoiJune-O Song Jung-Hee LeeTae-Yeon Seong 《Microelectronic Engineering》2011,88(10):3164-3167
The light output and electrical characteristics of GaN-based vertical light emitting diodes were investigated as a function of n-GaN thickness. The forward voltage increases from 3.34 to 3.42 V at an injection current of 350 mA as the n-GaN thickness decreases from 5.0 to 2.0 μm. Even at a high injection current of 2.0 A, LEDs with 2.0 μm-thick n-GaN reveal stable forward characteristics which are comparable to those of LEDs with 5.0 μm-thick n-GaN. All the samples exhibit almost the same reverse current up to approximately −8 V. The output power increases with decreasing n-GaN layer thickness. For example, LEDs with 2.0 μm-thick n-GaN yield about 12% higher light output power as compared to LEDs with 5.0 μm-thick n-GaN. Their light output power continuously increases without saturation as the injection current increases up to 1 A. The n-GaN thickness dependence of the electrical characteristics is described and discussed. 相似文献
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GaN-based nanoporous green LEDs with different pore depth have been fabricated by using anodic aluminum oxide (AAO) as dry etching mask. The experimental results show that the electrical properties of the nanoporous LEDs with different pore depths are similar, but for the optical properties, the LEDs with nanopores extended to the p-GaN layer exhibits the best performance, if increase the depth to MQWs or decrease to the ITO layer will both decrease the light output power (LOP). By calculating the light extraction efficiency using three-dimensional (3D) finite-difference time-domain method, the decrease of the light output is mainly attributed to the reduced light extraction efficiency when the pore depth stop at ITO transparent layer instead of p-type layer, while if the depth reach the MQWs, the deterioration of the QWs which is caused by dry etching damage will play an important role. This optimization would give a valuable guidance to the surface structure design for nanostructured GaN-based LEDs, such as surface roughening, photonic crystal, or top-down fabricated surface-plasmon enhanced LEDs. 相似文献
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随着太赫兹技术的应用和发展,对大功率太赫兹固态源的需求愈加迫切。文中基于GaN肖特基二极管(SBD)工艺设计并制造了具有高功率输出的170 GHz和340 GHz太赫兹倍频器,实现了340 GHz大功率太赫兹固态倍频链。采用多管芯GaN SBD提高器件功率承载能力,综合开展电路优化设计提升倍频性能,通过仿真研究和实验测试,验证了倍频器设计的有效性和先进性。170 GHz倍频器的实测峰值输出功率达到580 mW,倍频效率为14.5%。340 GHz倍频器的实测峰值输出功率为66 mW,倍频效率为12.5%。该太赫兹固态倍频链性能优良,在太赫兹系统中具有重要的应用价值。 相似文献