Optical Cavity Effects in InGaN Micro-Light-Emitting Diodes With Metallic Coating

We implement finite difference method (FDM) to calculate the optical cavity effects in InGaN micro-light-emitting diodes (LEDs) with metallic coating. The dispersion relation, mode profile, energy density
$W$
of electromagnetic field, cavity quality factor
$Q$
, and effective mode area
$A_{e\,f\,f}$
are theoretically investigated. The results show that although the strongest confinement of the field is achieved by surface plasmon modes at GaN/Ag interface, the energy density
$W$
is small inside the cavity, leading to a high effective mode area. Additionally, the cavity without metallic coating has the highest
$Q$
factors since no metal loss is involved. These results can serve as guidelines for the design and fabrication of high efficiency and high speed LEDs for the applications of solid-state lighting and visible-light communication.