Study on the light extraction efficiency of GaN-based light emitting diode by using the defects of the photonic crystals

Abstract

Many studies have shown that the photonic crystals and surface nanostructures can improve the light extraction efficiency of light emitting diode (LED). The defects and disorders exist in photonic crystals inevitably as the manufacturing technology limitations, and so the light extraction efficiency of LED will be changed correspondingly. In this work we perform a simulation study on defects and disorder of photonic crystals by the finite-difference time-domain (FDTD) method, and we speed up the FDTD by GPU acceleration technology. Simulation results show that a small number of defects in photonic crystals LED do not reduce the LED light extraction efficiency. Instead, the light extraction efficiency of LED will be increased by adding some defects into the photonic crystals. We give a detailed analysis of its physical mechanism. We design a kind of photonic crystals with defects, and its light extraction efficiency achieves 1.6 times that of the perfect photonic crystals.