Theoretical study of polarization-doped GaN-based light-emitting diodes

Insufficient hole injection is a major impediment to the luminescence efficiency of III-nitride light-emitting diodes(LEDs). In our previous work by Zhang[Appl. Phys. Lett.97,062103(2010)], high-density mobile three-dimensional hole gas is obtained in Mg-doped Al composition graded AlGaN layer with Al composition linearly decreasing from a certain value to0. In this paper, it is revealed by a theoretical study that the hole injection efficiency in blue-light GaN-based LEDs can be greatly enhanced by using this polarization-doped method. An increase in the electroluminescence intensity and the internal quantum efficiency in polarization-doped GaN-based LEDs is observed, in comparison with a conventional LED.?2011 American Institute of Physics