Selectively grown photonic crystal structures for high efficiency InGaN emitting diodes using nanospherical-lens lithography

Tongbo Wei, Kui Wu, Ding Lan, Qingfeng Yan, Yu Chen, Chengxiao Du, Junxi Wang, Yiping Zeng, Jinmin Li

Applied Physics Letters · 2012 · 53 citations · 16 references

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Abstract

We report a low-cost and high-throughput process for the fabrication of two-dimensional SiO2 photonic crystal (PhC) by nanospherical-lens photolithography method to improve the light extraction of GaN-based light-emitting diodes (LEDs). The PhC structures were realized by the selective area growth of p-GaN using SiO2 nanodisks, which were patterned utilizing a self-assembled nanosphere as an optical lens. Without prejudice to the electrical properties of LEDs, the light output power (at 350 mA) of LEDs with the SiO2 and corresponding air-hole PhC was enhanced by 71.3% and 49.3%, respectively, compared to that without PhC. The LEDs with selectively grown PhC structures were found to exhibit partial compression strain release and reduced emission divergence. The finite-difference time-domain simulation was also performed to further reveal the emission characteristics of PhC LEDs.

References

16