InGaN/GaN tunnel-injection blue light-emitting diodes

A charge asymmetric resonance tunneling (CART) structure was applied to nitride-based blue light emitting diodes (LEDs) to enhance their output efficiency. It was found that with a 20-nm-thick In/sub 0.18/Ga/sub 0.82/N electron emitter layer, we could increase the LED output intensity from 28.3 minicandela (mcd) to 43.2 mcd (i.e., a 53% increase). However, a further increase in electron emitter layer thickness will reduce the intensity due to relaxation. It was also found that we could decrease the 20 mA forward voltage from 4.16 V to 3.58 V with a proper electron emitter layer.