High efficiency top-emitting microcavity light-emitting diodes

Microcavity light emitting diodes (MCLEDs) present several interesting features compared to conventional LEDs such as narrow linewidth, improved directionality and high efficiency. We report here on MCLEDs with a top emitting geometry. The MCLED layers were grown using molecular beam epitaxy on GaAs substrates. They consist of a 3-period Be-doped distributed Bragg reflector (DBR) centered at 950 nm wavelength, a cavity containing three InGaAs quantum wells and a 15-periods Si-doped DBR. Different values for the wavelength detuning between spontaneous emission line and Fabry-Perot cavity mode were explored, between -40 nm and +10 nm. Devices sizes ranged from 420 x 420 mu m(2) to 22 x 22 mu m(2). As expected from simulations, the higher efficiencies are obtained when the detuning is in the -20 to 0 nm range. The devices exhibit then up to 10% external quantum efficiency, measured for a 62 degrees collection half-angle. After correction for the surface shadowing due to the grid p-contact, the efficiency increases to 14% and is practically independent of device size.

Published in:
Light-Emitting Diodes: Research, Manufacturing, And Applications Iii, 3621, 151-159
Presented at:
3rd Conference on Light-Emitting Diodes, SAN JOSE, CA, Jan 27-28, 1999

 Record created 2010-10-13, last modified 2018-03-18

Rate this document:

Rate this document:
(Not yet reviewed)