Demonstration Of Relaxed Ingan-Based Red Leds Grown With High Active Region Temperature

Red LEDs were grown by metalorganic chemical vapor deposition with a high active region temperature of 870 degrees C on a relaxed InGaN/GaN superlattice buffer. The buffer was 100% biaxially relaxed by the thermal decomposition of an InGaN underlayer, measured by high resolution X-ray diffraction. Fabricated LEDs showed a low forward voltage of 2.25 V at a current density of 25 Acm(-2) with no Al-containing layers in the active region, a peak emission wavelength of 633 nm at 200 Acm(-2) and an on-wafer peak external quantum efficiency of 0.05%. Uniform red emission and relaxation were observed across a two inch substrate.