AVS 51st International Symposium
    Science of Semiconductor White Light Topical Conference Wednesday Sessions
       Session WL+MS-WeA

Invited Paper WL+MS-WeA1
Material and Device Challenges of Deep UV Emitters

Wednesday, November 17, 2004, 2:00 pm, Room 304B

Session: Science of Semiconductor White Light II
Presenter: M.H. Crawford, Sandia National Laboratories
Authors: M.H. Crawford, Sandia National Laboratories
A.A. Allerman, Sandia National Laboratories
A.J. Fischer, Sandia National Laboratories
K.H.A. Bogart, Sandia National Laboratories
S.R. Lee, Sandia National Laboratories
W.W. Chow, Sandia National Laboratories
Correspondent: Click to Email
One of the new frontiers of light emitting diode research is the application of wide bandgap AlGaN alloys to achieve electroluminescence at 300 nm and shorter wavelengths. While most near-UV (380-400 nm) LEDs employ InGaN quantum well structures with GaN barriers, reaching deep UV wavelengths requires the growth of AlGaN alloys with aluminum concentrations of 50% and higher. In this presentation, we will review the present status of LED technology in the deep UV range and will discuss in detail the material and device challenges for achieving high performance devices. We will present data on LEDs that are grown by metal-organic vapor-phase epitaxy and employ flip-chip device geometries. These devices have yielded > 1 mW output powers in the 275-290 nm range under DC current operation. Critical device issues that will be discussed include performance under pulsed current injection, device lifetimes and an evaluation of the origins of deep level emission in the electroluminescence spectra. Electroluminescence at wavelengths shorter than 250 nm will be presented, and limitations of short wavelength performance will be discussed. Sandia is a multiprogram laboratory operated by Sandia Corporation for the United States Department of Energy’s National Nuclear Security Administration under Contract DE-AC04-94AL85000. This work is supported by DARPA under the SUVOS program.