title: Microtube Light-Emitting Diode Arrays with Metal Cores.
abstract: We report the fabrication and characteristics of vertical microtube light-emitting diode (LED) arrays with a metal core inside the devices. To make the LEDs, gallium nitride (GaN)/indium gallium nitride (In(x)Ga(1-x)N)/zinc oxide (ZnO) coaxial microtube LED arrays were grown on an n-GaN/c-aluminum oxide (Al2O3) substrate. The microtube LED arrays were then lifted-off the substrate by wet chemical etching of the sacrificial ZnO microtubes and the silicon dioxide (SiO2) layer. The chemically lifted-off LED layer was then transferred upside-down on other supporting substrates. To create the metal cores, titanium/gold and indium tin oxide were deposited on the inner shells of the microtubes, forming n-type electrodes inside the metal-cored LEDs. The characteristics of the resulting devices were determined by measuring electroluminescence and current-voltage characteristic curves. To gain insights into the current-spreading characteristics of the devices and understand how to make them more efficient, we modeled them computationally.
authors: Department of Physics and Astronomy, Institute of Applied Physics, and Research Institute of Advanced Materials, Seoul National University , Seoul 151-747, Korea.
authors: Youngbin
authors: Y
authors: Tchoe
authors: KU-KIST Graduate School of Converging Science and Technology, Korea University , Seoul 136-701, Korea.
authors: Chul-Ho
authors: CH
authors: Lee
authors: Department of Physics and Astronomy, Institute of Applied Physics, and Research Institute of Advanced Materials, Seoul National University , Seoul 151-747, Korea.
authors: Jun Beom
authors: JB
authors: Park
authors: Department of Physics and Astronomy, Institute of Applied Physics, and Research Institute of Advanced Materials, Seoul National University , Seoul 151-747, Korea.
authors: Hyeonjun
authors: H
authors: Baek
authors: Department of Physics and Astronomy, Institute of Applied Physics, and Research Institute of Advanced Materials, Seoul National University , Seoul 151-747, Korea.
authors: Kunook
authors: K
authors: Chung
authors: Department of Material Science and Engineering and Research Institute of Advanced Materials, Seoul National University , Seoul 151-744, Korea.
authors: Janghyun
authors: J
authors: Jo
authors: Department of Material Science and Engineering and Research Institute of Advanced Materials, Seoul National University , Seoul 151-744, Korea.
authors: Miyoung
authors: M
authors: Kim
authors: Department of Physics and Astronomy, Institute of Applied Physics, and Research Institute of Advanced Materials, Seoul National University , Seoul 151-747, Korea.
authors: Gyu-Chul
authors: GC
authors: Yi
keywords: current spreading; gallium nitride; light-emitting diodes; metal core; nanoarchitecture