Enhancing the light extraction efficiency of GaN-based LEDs

Pingjuan Niu; Yanling Li; Xiaoyun Li

doi:10.1117/12.760227

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20 November 2007 Enhancing the light extraction efficiency of GaN-based LEDs

Pingjuan Niu, Yanling Li, Xiaoyun Li

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Proceedings Volume 6828, Light-Emitting Diode Materials and Devices II; 682811 (2007) https://doi.org/10.1117/12.760227
Event: Photonics Asia 2007, 2007, Beijing, China

Abstract

GaN-based light-emitting diode (LED) has been widely used in recent years, and tremendous progress has been achieved in GaN-based semiconductor materials and relevant process. However, owing to the large refractive index contrast between GaN-based semiconductor materials and air, light can be easily totally internally reflected at the semiconductor/air interface, and the critical angle for light to escape from the semiconductor is small. Therefore, the light extraction efficiency for GaN-based LED is still low and needs improving. Some of the leading approaches to enhance light extraction efficiency of GaN-based LED such as surface texturing or roughening, omnidirectional reflectors, photonic crystals, laser liftoff, transparent electrode, patterned substrate and so on are introduced in detail. For each approach, how the variation in device structure or material improves the light extraction efficiency is analyzed thoroughly. At last, some of mentioned approaches that are promising are evaluated and viewed briefly.

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Pingjuan Niu, Yanling Li, and Xiaoyun Li "Enhancing the light extraction efficiency of GaN-based LEDs", Proc. SPIE 6828, Light-Emitting Diode Materials and Devices II, 682811 (20 November 2007); https://doi.org/10.1117/12.760227

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