Fabrication of high-performance 407nm violet light-emitting diode

High-performance 407nm violet InGaN multi-quantum-wells light-emitting diodes (LED) with an un-doped GaN current spreading layer were fabricated on sapphire substrate by using metal organic chemical vapor deposition technique. Different conditions were chosen to grow un-doped GaN layer as the current spreading layer in three LEDs. Using a 30nm high-temperature un-doped GaN layer, the output efficiency and high injection current luminance versus current (I–L) characteristics of our LED have been greatly improved. A LED with an output power of 7mW at an injection current of 20mA was achieved. In additional, the LED also shows an almost linear I–L characteristics at high injection current.