Enhanced Light Output in InGaN-Based Light-Emitting Diodes with Omnidirectional One-Dimensional Photonic Crystals

Abstract

We have successfully designed and fabricated GaN-based light-emitting diodes (LEDs) containing an omnidirectional one-dimensional photonic crystal (1D PC). The 1D PC is composed of alternatively stacked TiO2 and SiO2 layers designed to possess a photonic band gap (PBG) within the blue regime of interest. With the same multiple quantum well (MQW) emission peak at approximately 450 nm and a driving current of 20 mA, the light output powers of the LED with and without the 1D PC are approximately 11.7 and 6.5 mW, respectively. The enhancement in light extraction of our LED with 1D PC demonstrates that a properly designed omnidirectional 1D PC can have a higher reflectance and a wider reflection angle than a conventional distributed Bragg reflector (DBR). Our work shows promising potential for the enhancement of output powers of commercial light emitting devices.