Improved light extraction of GaN-based light-emitting diodes by ITO patterning with optimization design
- ISSN: 00381101
- DOI: 10.1016/j.sse.2009.10.005
The method of surface patterning of indium tin oxide (ITO) transparent current layer has been investigated in this study to improve the light extraction efficiency of GaN-based light-emitting diodes (LEDs). Optimized design of the patterns on ITO has been performed by ray-tracing simulation and LEDs with different periodic micro-circle structures on ITO have been fabricated. The light output power of the LEDs with the optimal patterns on ITO exhibited 46.4% enhancement compared to the conventional LEDs at 20 mA injection current without electrical degradation. Detailed processing parameters are also provided. It is indicated from the results that the surface-patterned ITO technique could have potential applications in high-power GaN-based LEDs. (C) 2009 Elsevier Ltd. All rights reserved.