Improved Light Extraction from Large-Area Vertical Light-Emitting Diodes with Deep Hole-Patterns Using Nanosphere Lithography
Abstract:The authors report on an improved light extraction method from large-area vertical light emitting diodes (VLEDs) with deep hole-patterns fabricated using nanosphere lithography. In order to produce the ordered deep-hole patterns on the n-type GaN surface, a 150 nm thick Ni dot mask formed via a lift-off process of the Ni coated onto a 500 nm diameter polystylene bead array was employed to enable deep etching. Three VLEDs—one as a reference with no patterns, and two with periodic 360 nm diameter hole patterns, one with 1.0 μm and the other with 1.5 μm depths on the n-type GaN surface, were prepared for comparison. The light output power measured for the VLEDs with the hole-patterns increased by 4.13 and 4.86 times, respectively, as compared to the reference VLED. These enhancements are attributed to the multiple scatterings of the light from the sidewall of the hole-patterns and to the increased surface area to which the light can approach. The higher light output power obtained for the VLEDs with the deep hole patterns might be due to a photon reabsorption reduction within the n-GaN layer.
Document Type: Research Article
Publication date: December 1, 2011
More about this publication?
- Journal for Nanoscience and Nanotechnology (JNN) is an international and multidisciplinary peer-reviewed journal with a wide-ranging coverage, consolidating research activities in all areas of nanoscience and nanotechnology into a single and unique reference source. JNN is the first cross-disciplinary journal to publish original full research articles, rapid communications of important new scientific and technological findings, timely state-of-the-art reviews with author's photo and short biography, and current research news encompassing the fundamental and applied research in all disciplines of science, engineering and medicine.
- Editorial Board
- Information for Authors
- Subscribe to this Title
- Terms & Conditions
- Ingenta Connect is not responsible for the content or availability of external websites