载流子定位和 Shockley-read-Hall 复合对 InGaN LED 电致发光空间分布的影响

摘要：我们研究了蓝色和绿色发光二极管 (LED) 在电流应力老化过程中发射的不同行为。引入微观高光谱成像来测量峰 值强度、峰值能量和半峰全宽的空间分辨映射。此外，测量了外部量子效率与注入电流的关系图，以确定基于两级模型 的 ShockleyRead-Hall (SRH) 非辐射复合率的范围。因此，提出了一个现象学模型来解释载流子局域化和 SRH 复合之间 的竞争机制。在蓝色 LED 的情况下，局域化状态下辐射复合的增加抵消了点缺陷内的 SRH 非辐射复合。而在绿色 LED 的情况下，SRH 复合的增强和载流子局域化的减弱共同消除了辐射复合。

关键词：发光二极管、显微高光谱成像、载流子定位、肖克利-里德-霍尔复合。

期刊：Photonics Journal- IEEE

DOI：10.1109/JPHOT.2018.2880319 1943-0655 © 2018

设备：GaiaMicro

Effect of Carrier Localization and Shockley-Read-Hall Recombination on the Spatial Distribution of Electroluminescence in InGaN LEDs

Abstract：We investigate divergent behaviors in the emission of blue and green lightemitting diodes (LEDs) when they are subjected to the current-stress aging. Microscopic hyperspectral imaging is introduced to measure spatially resolved mappings of the peak intensity, the peak energy, and the full width at half maximum. Also, plots of external quantum efficiency versus injection current are measured to determine the extent of the ShockleyRead-Hall (SRH) nonradiative recombination rate based on the two-level model. As a result, a phenomenological model is proposed to account for the competitive mechanism between the carrier localization and the SRH recombination. In the blue LED case, the increase in the radiative recombination within localization states cancels the SRH nonradiative recombination within point defects. While in the green LED case, the enhancement of SRH recombination and the remission of carrier localization jointly kill the radiative recombination.

Keywords：Light-emitting diodes, microscopic hyperspectral imaging, carrier localization, Shockley-Read-Hall recombination.