Influence of patterned sapphire substrates with different symmetry on the light output power of InGaN-based LEDs

Yao-Hong You; Vin-Cent Su; Ti-En Ho; Bo-Wen Lin; Ming-Lun Lee; Atanu Das; Wen-Ching Hsu; Chieh-Hsiung Kuan; Ray-Ming Lin

doi:10.1186/1556-276X-9-596

Influence of patterned sapphire substrates with different symmetry on the light output power of InGaN-based LEDs

Nanoscale Res Lett. 2014 Nov 3;9(1):596. doi: 10.1186/1556-276X-9-596. eCollection 2014.

Authors

Yao-Hong You¹, Vin-Cent Su¹, Ti-En Ho², Bo-Wen Lin³, Ming-Lun Lee¹, Atanu Das², Wen-Ching Hsu⁴, Chieh-Hsiung Kuan¹, Ray-Ming Lin²

Affiliations

¹ Graduate Institute of Electronic Engineering and Department of Electrical Engineering, National Taiwan University, No. 1, Roosevelt Road Section 4, Daan District, Taipei 10617, Taiwan.
² Graduate Institute of Electronic Engineering and Green Technology Research Center, Chang Gung University, 259 Wen-Hwa 1st Road, Kwei-Shan, Tao-Yuan 333, Taiwan.
³ Department of Materials Science and Engineering, National Chiao Tung University, No. 1001, Daxue Road, East District, Hsinchu 300, Taiwan.
⁴ Sino-American Silicon Products Incorporated, No. 8, Industrial East Road 2, Science-Based Industrial Park, Hsinchu 300, Taiwan.

Abstract

This paper aims to investigate the light output power (LOP) of InGaN-based light-emitting diodes (LEDs) grown on patterned sapphire substrates (PSSs) with different symmetry. The GaN epitaxial layers grown on the hexagonal lattice arrangement PSS (HLAPSS) have a lower compressive strain than the ones grown on the square lattice arrangement PSS (SLAPSS). The quantum-confined Stark effect (QCSE) is also affected by the residual compressive strain. Based on the experimentally measured data and the ray tracing simulation results, the InGaN-based LED with the HLAPSS has a higher LOP than the one with the SLAPSS due to the weaker QCSE within multiple-quantum wells (MQWs).

Keywords: GaN; Light-emitting diodes; Patterned sapphire substrates; Quantum-confined Stark effect.