Enhanced hole transport of nonpolar InGaN-based light-emitting diodes with lateral p-type superlattice doping structure

Abstract

In this work, we propose a novel structure for nonpolar (10–10)-plane InGaN-based light-emitting diode (LED) using a lateral p-type Al0.2Ga0.8N/GaN superlattice structure as the hole injection layer. The main objective is to increase the hole concentration and facilitate vertical hole injection. The nonpolar InGaN-based LED lacks polarization along the growth plane (10–10), but the lateral direction along [0001] exhibits strong polarization. Therefore, the Al0.2Ga0.8N/GaN superlattice structure, which is periodic along the [0001] direction, induces net polarization charges at the GaN/Al0.2Ga0.8N interface, resulting in increased ionization rates of the acceptors. Additionally, the high-density two-dimensional hole gases formed at the Al0.2Ga0.8N/GaN interfaces along the [0001] direction can efficiently inject vertically into the quantum wells. Based on the numerical simulation results, the proposed LED structure offers improved electrical characteristics, effective hole injection, and enhanced optical performance compared to the nonpolar LED with conventional p-type doping structure.