Title :
High-efficiency red and infrared light-emitting diodes using radial outcoupling taper
Author :
Schmid, Wolfgang ; Scherer, Marcus ; Karnutsch, Christian ; Plossl, A. ; Wegleiter, Walter ; Schad, Sven-Silvius ; Neubert, Barbara ; Streubel, Klaus
Author_Institution :
OSRAM Opto Semicond., Regensburg, Germany
Abstract :
In this paper, we give an overview of light-emitting diodes (LEDs) with radial tapers. Light is generated in the very center of a circularly symmetrical structure and is outcoupled at a tapered ring. Encapsulated devices with an emission wavelength of 980 nm achieve wallplug efficiencies of 48%. Non-encapsulated InGaAlP-based red-emitting LEDs show quantum efficiencies of 13%. A new device design combines the taper with a wafer-scale soldering technique promising a feasible fabrication method
Keywords :
encapsulation; light emitting diodes; soldering; wafer bonding; 13 percent; 48 percent; 980 nm; InGaAlP; circularly symmetrical structure; emission wavelength; encapsulated devices; extraction efficacy; high-efficiency infrared light-emitting diodes; high-efficiency red light-emitting diodes; metal-mirror-based devices; nonencapsulated InGaAlP-based red-emitting LEDs; overview; quantum efficiencies; radial outcoupling taper; tapered ring; wafer scale soldering technique; wallplug efficiencies; Fabrication; Light emitting diodes; Mirrors; Optical propagation; Optical reflection; Ray tracing; Semiconductor device modeling; Semiconductor diodes; Semiconductor thin films; Soldering;
Journal_Title :
Selected Topics in Quantum Electronics, IEEE Journal of
DOI :
10.1109/2944.999178
