Enhanced waveguide-type ultraviolet electroluminescence from ZnO/MgZnO core/shell nanorod array light-emitting diodes via coupling with Ag nanoparticles localized surface plasmons

Abstract

Localized surface plasmon (LSP) enhanced waveguide-type ultraviolet light-emitting diodes (LEDs) were fabricated by sputtering Ag nanoparticles (Ag-NPs) onto ZnO/MgZnO core/shell nanorod array (CS-NRA)/p-GaN heterostructures. A ∼9-fold enhancement of ZnO ultraviolet electroluminescence (EL) was demonstrated by the Ag-NPs decorated LED compared with the device without Ag-NPs. Angle-dependent EL measurements, as well as finite-difference time-domain simulations of the EL intensity spatial distribution, confirmed the waveguide-type EL transmission mode along the NR's axial direction. The increased spontaneous emission rate observed in time-resolved spectroscopy suggested that the ZnO EL enhancement was attributed to LSP-exciton/polariton coupling. However, a direct coupling is very difficult to achieve between Ag-LSPs and electron-hole pairs in the active region due to their "remote" separation. Thereby, two possible models involving the dynamic process of interactions among excitons, photons, and LSPs, were established to understand the selective enhancement of ZnO EL.

Assessing hardness and fracture toughness in sintered zinc oxide ceramics through indentation technique

“…It is an n-type semiconductor with wide-band gap (E g ¼3.37 eV) and large exciton binding energy of 60 meV at room temperature. ZnO is considered the most favorable candidate for use in various opto-electronic devices like solar cells, photo detectors, light-emitting diodes, sensors, piezoelectric devices [1][2][3]. It shows promising diluted magnetic semiconductor properties that are useful in spintronics systems.…”

Ultraviolet Electroluminescence from ZnS@ZnO Core–Shell Nanowires/p-GaN Introduced by Exciton Localization

“…However, it is known that the optoelectronic properties of these devices are greatly influenced by the surface properties of ZnO nanostructures. 13,[19][20][21][22][23] Thus, various approaches such as quantum dots sensitization, introducing of localized surface plasmon or localized excitons have been adopted to optimize the performance of ZnO nanostructures. 21,[22][23][24][25][26] Herein, we propose the ZnS@ZnO core-shell nanowires/p-GaN structure heterojunctions.…”

“…Due to the advanced physical and chemical properties, the integration of ZnO nanostructures (nanowires or quantum dots) with GaN could be a feasible approach to obtain light-emitting diodes (LEDs) with high performance. 13,15,19,20 Several kinds of low-dimensional nanostructures have been studied extensively. However, it is known that the optoelectronic properties of these devices are greatly influenced by the surface properties of ZnO nanostructures.…”

One-Dimensional Zinc Oxide Nanomaterials for Application in High-Performance Advanced Optoelectronic Devices

“…To further improve the performance of LEDs, the two methods mentioned above can be combined. Zhang et al [100] fabricated LSP-enhanced waveguide-type UV LEDs via sputtering Ag nanoparticles onto ZnO/MgZnO core/shell nanorod array/p-GaN film heterostructures. After decoration with Ag nanoparticles, the UV emission intensity of the ZnO/MgZnO core/shell nanorod array showed ã 9-fold enhancement compared with that of the device without Ag nanoparticles because of coupling with LSPs.…”