Department of Electronic and Computer Engineering, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong SAR, China.
HKUST-Shenzhen Research Institute, No. 9 Yuexing first RD, South Area, Hi-tech Park, Nanshan, Shenzhen, 518057, China.
Nat Commun. 2019 Feb 13;10(1):727. doi: 10.1038/s41467-019-08561-y.
Metal halide perovskite has emerged as a promising material for light-emitting diodes. In the past, the performance of devices has been improved mainly by optimizing the active and charge injection layers. However, the large refractive index difference among different materials limits the overall light extraction. Herein, we fabricate efficient methylammonium lead bromide light-emitting diodes on nanophotonic substrates with an optimal device external quantum efficiency of 17.5% which is around twice of the record for the planar device based on this material system. Furthermore, optical modelling shows that a high light extraction efficiency of 73.6% can be achieved as a result of a two-step light extraction process involving nanodome light couplers and nanowire optical antennas on the nanophotonic substrate. These results suggest that utilization of nanophotonic structures can be an effective approach to achieve high performance perovskite light-emitting diodes.
金属卤化物钙钛矿已成为发光二极管有前途的材料。在过去，主要通过优化活性层和电荷注入层来提高器件的性能。然而，不同材料之间的大折射率差限制了整体光提取。在此，我们在具有最佳器件外量子效率为 17.5%的纳米光子学衬底上制造了高效的甲脒铅溴发光二极管，这大约是基于该材料系统的平面器件的记录的两倍。此外，光学建模表明，由于纳米光子学衬底上的纳米穹光耦合器和纳米线光学天线的两步光提取过程，可以实现 73.6%的高光提取效率。这些结果表明，利用纳米光子结构可以是实现高性能钙钛矿发光二极管的有效方法。
