Self-Aligned Hierarchical ZnO Nanorod/NiO Nanosheet Arrays for High Photon Extraction Efficiency of GaN-Based Photonic Emitter

Abstract

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.

Self-array of one-dimensional GaN nanorods using the electric field on dielectrophoresis for the photonic emitters of display pixel

“…This is due to their outstanding properties, such as high efficiency and high stability. 1–3 Among various applications, the display is one of the industries in high demand for III-nitride PEs. The first use of III-nitride PEs as a display light source was in backlight units (BLUs) of the liquid crystal display (LCD) panel.…”

Editorial for the Special Issue on Wide Bandgap Based Devices: Design, Fabrication and Applications

“…Nine of the papers, [ 4 , 5 , 6 , 7 , 8 , 9 , 10 , 11 , 12 ], explore various designs of wide bandgap high power devices. The remaining papers cover various applications based on wide bandgaps, such as ZnO Nanorods for High Photon Extraction Efficiency of GaN-Based Photonic Emitter [ 13 ], InGaZnO Thin-Film Transistors [ 14 ], Wide Band Gap WO 3 Thin Film [ 15 ], Silver Nanorings [ 16 , 17 ] and InGaN Laser Diode [ 18 , 19 , 20 ].…”

“…Besides, Lee et al [ 13 ] demonstrated self-aligned hierarchical ZnO nanorod nanosheet arrays on a conventional photonic emitter with a wavelength of 430 nm with an improved optical output power. Zhang et al [ 14 ] improved the electrical performance and bias-stress stability of amorphous InGaZnO thin-film transistors using buried-channel devices with multiple-stacked channel layers.…”