Enhanced output power of InGaN/GaN light-emitting diodes with a multilayered structure of AlGaN/GaN electron blocking layer

GaN-based multiple quantum well (MQW) light emitting diodes (LEDs) are promising to replace the conventional incandescent and fluorescent lamps due to recent improvements in material quality and device.Blue InGaN/GaN multiple quantum well light-emitting diodes with the conventional AlGaN and AlGaN-GaN-AlGaN (AGA) and many other novel structure electron blocking layer(EBL) are numerically investigated.When either AlGaN layer of a AGA EBL is inserted by a GaN layer leading to a multilayered structure,the simulation results show the Fermi level and energy gap of the EBL make a remarkable difference owing to the changed structure and the device with the new structure creates much higher output power as compared to those with conventional structure and AGA structure due to the enhancement of the electron confiment and improvement of the hole injection, which are induced by a higher electron barrier height and a lower hole barrier height in the new structure.