Origin of GaN-InGaN-GaN barriers in enhancing the hole injection for InGaN/GaN green light-emitting diodes

摘要

In this work, we propose to insert an Ino.07Gao.93N layer into the GaN quantum barriers for InGaN/GaN green light-emitting diodes (LEDs) to achieve the enhanced hole injection and improve the internal quantum efficiency (IQE). Nevertheless, we also find that the insertion layer cannot be too thin, and a properly thick insertion layer is recommended, because the polarization induced electric field in the GaN/In_(0.07)Ga_(0.93)N/GaN quantum barriers can accelerate holes, and thereby the hole blocking effect at the GaN/In_(0.07)Ga_(0.93)N interfaces and the increase for the valence band barrier height of p-EBL will be less significant. Other advantage is that the insertion Ino.07Gao.93N layer can also reduce the polarization induced electric field in the quantum wells, which is helpful to increase the radiative recombination rate.