Lee Won-Seok, Kwon Soon-Hwan, Choi Hee-Jung, Im Kwang-Gyun, Lee Hannah, Oh Semi, Kim Kyoung-Kook
Department of Advanced Convergence Technology, Research Institute of Advanced Convergence Technology, Korea Polytechnic University, Gyeonggi-do 15073, Korea.
Department of Nano & Semiconductor Engineering, Korea Polytechnic University, Gyeonggi-do 15073, Korea.
Micromachines (Basel). 2020 Mar 26;11(4):346. doi: 10.3390/mi11040346.
Advancements in nanotechnology have facilitated the increased use of ZnO nanostructures. In particular, hierarchical and core-shell nanostructures, providing a graded refractive index change, have recently been applied to enhance the photon extraction efficiency of photonic emitters. In this study, we demonstrate self-aligned hierarchical ZnO nanorod (ZNR)/NiO nanosheet arrays on a conventional photonic emitter (C-emitter) with a wavelength of 430 nm. These hierarchical nanostructures were synthesized through a two-step hydrothermal process at low temperature, and their optical output power was approximately 17% higher than that of ZNR arrays on a C-emitter and two times higher than that of a C-emitter. These results are due to the graded index change in refractive index from the GaN layer inside the device toward the outside as well as decreases in the total internal reflection and Fresnel reflection of the photonic emitter.
纳米技术的进步推动了氧化锌（ZnO）纳米结构的更多应用。特别是，具有渐变折射率变化的分级和核壳纳米结构，最近已被用于提高光子发射器的光子提取效率。在本研究中，我们展示了在波长为430 nm的传统光子发射器（C型发射器）上的自对准分级氧化锌纳米棒（ZNR）/氧化镍（NiO）纳米片阵列。这些分级纳米结构通过两步低温水热法合成，其光输出功率比C型发射器上的ZNR阵列高出约17%，比C型发射器高出两倍。这些结果归因于从器件内部的氮化镓（GaN）层到外部的折射率渐变变化，以及光子发射器的全内反射和菲涅尔反射的减少。
