...
  • 主题
高级搜索  >
历史搜索 清空历史
首页> 外文期刊>Journal of Applied Physics >Impact of active layer design on InGaN radiative recombination coefficient and LED performance
【24h】

Impact of active layer design on InGaN radiative recombination coefficient and LED performance

机译：有源层设计对InGaN辐射复合系数和LED性能的影响

获取原文
获取原文并翻译 | 示例
           
页面导航
  • 摘要
  • 著录项
  • 相似文献
  • 相关主题

摘要

The relative roles of radiative and nonradiative processes and the polarization field on the light emission from blue (～425 nm) InGaN light emitting diodes (LEDs) have been studied. Single and multiple double heterostructure (DH) designs have been investigated with multiple DH structures showing improved efficiencies. Experimental results supported by numerical simulations of injection dependent electron and hole wavefunction overlap and the corresponding radiative recombination coefficients suggest that increasing the effective active region thickness by employing multiple InGaN DH structures separated by thin and low barriers is promising for LEDs with high efficiency retention at high injection. The use of thin and low barriers is crucial to enhance carrier transport across the active region. Although increasing the single DH thickness from 3 to 6 nm improves the peak external quantum efficiency (EQE) by nearly 3.6 times due to increased density of states and increased emitting volume, the internal quantum efficiency (IQE) suffers a loss of nearly 30%. A further increase in the DH thickness to 9 and 11 nm results in a significantly slower rate of increase of EQE with current injection and lower peak EQE values presumably due to degradation of the InGaN material quality and reduced electron-hole spatial overlap. Increasing the number of 3 nm DH active regions separated by thin (3 nm) In_(0.06)Ga_(0.94)N barriers improves EQE, while maintaining high IQE (above 95% at a carrier concentration of 10~(18) cm~(-3)) and showing negligible EQE degradation up to 550 A/cm~2 in 400 × 400 μm~2 devices due to increased emitting volume and high radiative recombination coefficients and high IQE. Time-resolved photoluminescence measurements revealed higher radiative recombination rates with increasing excitation due to screening of the internal field and enhanced electron and hole overlap at higher injection levels. To shed light on the experimental observations, the effect of free-carrier screening on the polarization field at different injection levels and the resulting impact on the quantum efficiency were investigated by numerical simulations.
机译：研究了辐射和非辐射过程以及偏振场对蓝色（〜425 nm）InGaN发光二极管（LED）发光的相对作用。已经研究了具有改善的效率的多个DH结构的单和多个双异质结构（DH）设计。注入依赖性电子和空穴波函数重叠的数值模拟以及相应的辐射复合系数所支持的实验结果表明，通过采用由薄壁垒和低壁垒隔开的多个InGaN DH结构来增加有效有源区厚度，对于在高效率下保持高效率的LED很有希望。注射。薄和低的势垒的使用对于增强跨有源区的载流子传输至关重要。尽管由于状态密度的增加和发射体积的增加，单个DH厚度从3 nm增加到6 nm可以使峰值外部量子效率（EQE）提高近3.6倍，但内部量子效率（IQE）却损失了近30％。 DH厚度进一步增加到9和11 nm会导致注入电流时EQE的增加速度明显变慢，并且可能由于InGaN材料质量的降低和电子空穴空间重叠的减少而导致EQE峰值降低。增加3 nm的In_（0.06）Ga_（0.94）N薄势垒分隔的3 nm DH有源区的数量可以改善EQE，同时保持较高的IQE（载流子浓度10〜（18）cm〜（95％以上） -3））并显示出在400×400μm〜2的器件中，高达550 A / cm〜2的EQE可以忽略不计，这是由于发射量增加，辐射复合系数高和IQE较高。时间分辨的光致发光测量结果表明，由于屏蔽了内部电场，在更高的注入水平下，电子和空穴的重叠增强，激发的辐射复合率更高。为了阐明实验结果，通过数值模拟研究了自由载流子筛选对不同注入水平下极化场的影响以及由此对量子效率的影响。

著录项

  • 来源
    《Journal of Applied Physics》 |2012年第6期|p.063112.1-063112.8|共8页
  • 作者

    X. Li; S. Okur; F. Zhang; V. Avrutin; UE. OEzguer; H. Morkoc; S. M. Hong; S. H. Yen; T. S. Hsu; A. Matulionis;

  • 作者单位

    Department of Electrical and Computer Engineering, Virginia Commonwealth University, Richmond,Virginia 23284, USA;

    Department of Electrical and Computer Engineering, Virginia Commonwealth University, Richmond,Virginia 23284, USA;

    Department of Electrical and Computer Engineering, Virginia Commonwealth University, Richmond,Virginia 23284, USA;

    Department of Electrical and Computer Engineering, Virginia Commonwealth University, Richmond,Virginia 23284, USA;

    Department of Electrical and Computer Engineering, Virginia Commonwealth University, Richmond,Virginia 23284, USA;

    Department of Electrical and Computer Engineering, Virginia Commonwealth University, Richmond,Virginia 23284, USA;

    EP1STAR Corporation, Hsinchu 300, Taiwan;

    EP1STAR Corporation, Hsinchu 300, Taiwan;

    EP1STAR Corporation, Hsinchu 300, Taiwan;

    Semiconductor Physics Institute of Center for Physical Science and Technology, Vilnius, Lithuania;

  • 收录信息 美国《科学引文索引》(SCI);美国《工程索引》(EI);美国《生物学医学文摘》(MEDLINE);
  • 原文格式 PDF
  • 正文语种 eng
  • 中图分类
  • 关键词

相似文献

  • 外文文献
  • 中文文献
  • 专利
获取原文

客服邮箱：kefu@zhangqiaokeyan.com

京公网安备：11010802029741号 ICP备案号：京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有

  • 客服微信

  • 服务号