Improved emission efficiency of a-plane GaN light emitting diodes with silica nano-spheres integrated into a-plane GaN buffer layer

Abstract

A simple and inexpensive technique to improve the emission efficiency of nonpolar a-plane light emitting diodes (LEDs) is proposed. The 3-dimensional growth nature of a-plane GaN was utilized to form the regrowth template of a-plane GaN. Subsequently, the controlled integration of silica nano-spheres (CIS) into the regrowth template is performed to improve the crystal quality of a-plane GaN by epitaxial lateral overgrowth method. In addition, the CIS improves light extraction by the scattering process. The light output power from the CIS a-plane GaN LEDs showed 130%-150% increase compared to that of LED without silica nano-spheres.This work was supported by the Brain Korea 21 (BK21) program, World Class University (WCU) program (R31-2008-000-10075-0) of the Ministry of Education of Korea, and the Technology Innovation Program (Industrial Strategic technology development program, 10035430, Development of high efficiency light emitting diode for illumination) funded by the Ministry of Knowledge Economy (MKE, Korea)