An AlGaN tunnel junction light emitting diode operating at 255 nm
An AlGaN tunnel junction light emitting diode operating at 255 nm
复制标题
DOI：
10.1063/5.0036286
复制
发表时间：
2020-12
影响因子：
4
通讯作者：
A. Pandey;J. Gim;R. Hovden;Z. Mi
中科院分区：
文献类型：
--
作者：
A. Pandey;J. Gim;R. Hovden;Z. Mi
我们报告的演示高性能隧道结深紫外（UV）发光二极管（LED）的使用等离子体辅助分子束外延。该器件的异质结构生长在稍微富Ga的条件下，以促进在有源区中形成纳米级簇。该器件在255 nm处工作，最大外量子效率为7.2%，壁插为4%，比以前报道的在该波长下工作的隧道结器件高出近一到两个数量级。该器件表现出高度稳定的发射，随着电流的增加，具有几乎恒定的发射峰，这是由于与富Ga纳米团簇的存在相关的强电荷载流子限制。然而，在相对低的电流密度下观察到效率下降。详细的温度依赖性测量表明，深紫外LED的效率下降的存在主要是由于电子溢出。由AIP Publishing授权出版。https://doi.org/10.1063/5.0036286 UV-C波长范围内的光（10%.先前的工作已经研究了隧道结的厚度和p-AlGaN层的掺杂对器件特性的关键影响。氮化物隧道结结构的早期研究也表明，载流子的运输通过隧道结主要是由transpassisted隧道，表明关键的作用，将应用物理快报。117，241101（2020）; doi：10.1063/5.0036286 117，241101-1由AIP Publishing Applied Physics Letters授权发布文章scitation.org/journal/apl
We report on the demonstration of high-performance tunnel junction deep ultraviolet (UV) light-emitting diodes (LEDs) by using plasmaassisted molecular beam epitaxy. The device heterostructure was grown under slightly Ga-rich conditions to promote the formation of nanoscale clusters in the active region. The device operates at 255 nm with a maximum external quantum efficiency of 7.2% and wall-plug of 4%, which are nearly one to two orders of magnitude higher than those of previously reported tunnel junction devices operating at this wavelength. The devices exhibit highly stable emission, with a nearly constant emission peak with increasing current, due to the strong charge carrier confinement related to the presence of Ga-rich nanoclusters. Efficiency droop, however, is observed at relatively low current densities. Detailed temperature-dependent measurements suggest that the presence of efficiency droop of deep UV LEDs is largely due to electron overflow. Published under license by AIP Publishing. https://doi.org/10.1063/5.0036286 Light within the UV-C wavelength range (10%. Previous work has investigated the critical effect of the thickness of the tunnel junction and doping of the p-AlGaN layers on device characteristics. Earlier studies on nitride tunnel junction structures have also shown that the transport of carriers across the tunnel junction is primarily determined by trapassisted tunneling, indicating the crucial role of incorporating Appl. Phys. Lett. 117, 241101 (2020); doi: 10.1063/5.0036286 117, 241101-1 Published under license by AIP Publishing Applied Physics Letters ARTICLE scitation.org/journal/apl