Theoretical analysis of polarization characteristics of InGaN/GaN LEDs with photonic crystals

Abstract

We investigated theoretically the polarization characteristics of GaN-based green (525 nm) light-emitting diodes (LEDs) with photonic crystals (PCs) using a three-dimensional finite difference time domain method. The light extraction efficiency depends strongly on the photonic bandgap (PBG) position relative to a frequency (a/λ) and the depth of air hole for transverse electric (TE) and transverse magnetic (TM) polarizations. The maximum extraction efficiency was achieved when the frequency of a/λ was matched within PBG region, leading to about 29% (22%) higher than the conventional LED without photonic crystals for TE (TM) polarization. It is found that the polarization of light can be controlled by the a/λ in PC structure.