Nitride-based blue light-emitting diodes with multiple Mg x N y /GaN buffer layers
GaN epitaxial layers and nitride-based light-emitting diodes (LEDs) structures with a conventional single low-temperature (LT) GaN buffer layer and multiple MgxNy/GaN buffer layers were prepared by metalorganic chemical vapor deposition. It was found that crystal quality of the GaN epilayer prepared on multiple MgxNy/GaN buffer layers was significantly better than that prepared with conventional low-temperature GaN nucleation layer. With the multiple MgxNy/GaN buffer layers, it was also found that 20mA LED output power can be enhanced by 12%, as compared to the conventional LED. Such an enhancement in output power could be attributed to the reduction of threading dislocation induced nonradiative recombination centers using 12-pairs MgxNy/GaN buffer layers.