Wafer-bonded thin-film surface-roughened light emitting diodes

摘要

We propose a new process for thin-film surface-textured LEDs that provides uniform current injection for both top and bottom contacts. The structure uses a partially conductive mirror. This eliminates the need for thick epitaxial layers and makes it possible to fabricate very large LEDs. Furthermore, the new process allows to obtain both high external quantum efficiency and high wallplug efficiency. 400x400 μm GaInP/AlGaInP LEDs reach maximum external quantum efficiencies of 35% at 12mA without encapsulation. The wallplug efficiency reaches 34% at 2.6 mA. At an operating current of 60 mA, the devices emit 30 mW of light.