Article révisé par les pairs
Résumé : Very high external efficiencies have been reported from surface-textured thin-film light-emitting diodes. We have developed a novel process for the wafer-scale fabrication of surface-textured thin-film LEDs, avoiding the use of wet thermal oxidation and epitaxial lift-off. The LEDs consist of a double-mesa structure with a structured gold reflector serving simultaneously as a p-contact. The light emission occurs on the side of the original GaAs substrate, which is removed by selective etching after glueing the sample with the processed side onto a carrier substrate. The light emission of the devices is fully confined within the diameter of the LED itself. In comparison to our previously reported LEDs, the series resistance has been significantly reduced by the current injection through the mirror. 85 μm diameter GaAs/AlGaAs LEDs reach maximum external quantum efficiencies of 42% before and 51% after encapsulation. Encapsulated devices reach a maximum wallplug efficiency of 47% at a current of 3.5 mA. At an operating current of 20 mA, they emit 14 mW of light. As a first result on 650 nm GaInP/AlGaInP LEDs we obtained external quantum efficiencies of 28% for unencapsulated devices with a diameter of 75 μm. At a drive current of 8 mA the LEDs emit 3.4 mW of light. © 2002 SPIE · 0277-786X/02/$15.00.