Tuning photonic crystal fabrication by nanosphere lithography and surface treatment of AlGaN-based ultraviolet light-emitting diodes

Kuan W.A. Chee; Wei Guo; John R. Wang; Yong Wang; Yue-e Chen; Jichun Ye

Materials & Design (Dec 2018)

Tuning photonic crystal fabrication by nanosphere lithography and surface treatment of AlGaN-based ultraviolet light-emitting diodes

Kuan W.A. Chee,
Wei Guo,
John R. Wang,
Yong Wang,
Yue-e Chen,
Jichun Ye

Affiliations

Kuan W.A. Chee: Department of Electrical and Electronic Engineering, Faculty of Science and Engineering, The University of Nottingham Ningbo, Ningbo 315100, Zhejiang, China; Ningbo Institute of Materials Technology and Engineering, Chinese Academy of Sciences, Ningbo 315201, Zhejiang, China; Laser Research Institute, Shandong Academy of Sciences, Shanyisuo Building, 37 Miaoling Road, Laoshan District, Qingdao 226100, Shandong, China; Corresponding author at: Department of Electrical and Electronic Engineering, Faculty of Science and Engineering, The University of Nottingham Ningbo, Ningbo 315100, Zhejiang, China.
Wei Guo: Ningbo Institute of Materials Technology and Engineering, Chinese Academy of Sciences, Ningbo 315201, Zhejiang, China
John R. Wang: School of Electrical and Computer Engineering, Cornell University, Ithaca, NY 14853, USA
Yong Wang: Laser Research Institute, Shandong Academy of Sciences, Shanyisuo Building, 37 Miaoling Road, Laoshan District, Qingdao 226100, Shandong, China
Yue-e Chen: College of Science, Yanshan University, Qinhuangdao 066004, Hebei, China
Jichun Ye: Ningbo Institute of Materials Technology and Engineering, Chinese Academy of Sciences, Ningbo 315201, Zhejiang, China

Journal volume & issue: Vol. 160
pp. 661 – 670

Abstract

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Photonic crystal processing was performed using nanosphere lithography as a low-cost procedure to enhance the quantum efficiency of AlGaN-based ultraviolet light emitting diodes. Spectral transmissivity/reflectivity and photoluminescence measurements, in conjunction with finite-element modeling and electromagnetic simulations, provide an indication of radiance enhancement with a photonic crystal periodicity comparable to the emission wavelength. To recondition the plasma-damaged sidewalls, post-processing methods based on high temperature annealing and surface treatment were evaluated, which in general, established a significant increase in light extraction efficiency. X-ray photoelectron spectroscopy clarified the formation of surface oxides and hydroxides on the as-fabricated nanostructures, and their dissolution after wet-chemical processing is linked to enhanced optical output. Hydroxyl-termination was found to prevail after KOH etching, but significantly reduced after HCl or H3PO4 treatment. The two-step sequence of HCl followed by KOH treatment provided the best quality nanotextured surface for optical emission in this study, as indicated by the nearly 14.5-fold enhancement in photoluminescence intensity. Keywords: Photonic crystals, Ray tracing, Photoluminescence, Periodic nanostructures, Etching, Heat treatment

Published in Materials & Design

ISSN: 0264-1275 (Print); 1873-4197 (Online)
Publisher: Elsevier
Country of publisher: United Kingdom
LCC subjects: Technology: Electrical engineering. Electronics. Nuclear engineering: Materials of engineering and construction. Mechanics of materials
Website: https://www.journals.elsevier.com/materials-and-design

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