Obvious improvement of light extraction obtained by anodic aluminum oxide coverage on GaN surface

• Published in: Applied physics. A, Materials science & processing Vol. 110; no. 1; pp. 35 - 39
• Main Authors: Yu, Z. G., Yang, G. F., Chen, P., Liu, R. H., Zhao, H., Liu, B., Hua, X. M., Xie, Z. L., Xiu, X. Q., Han, P., Lu, H., Song, X. Y., Zhang, R., Zheng, Y. D.
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Springer-Verlag 2013; Springer
• Subjects: Aluminum oxide; Anodic; Characterization and Evaluation of Materials; Condensed Matter Physics; Condensed matter: electronic structure, electrical, magnetic, and optical properties; Exact sciences and technology; Extraction; Gallium nitrides; Indium gallium nitrides; Machines; Manufacturing; Nanocomposites; Nanostructure; Nanotechnology; Optical and Electronic Materials; Optical properties and condensed-matter spectroscopy and other interactions of matter with particles and radiation; Photoluminescence; Physics; Physics and Astronomy; Porosity; Processes; Rapid Communication; Surfaces and Interfaces; Thin Films; Silica Film; Effective Refractive Index; Enhancement Factor; Anodic Aluminum Oxide; Light Extraction; Gallium Nitrides; Ternary compounds; Photoluminescence; Multiple quantum well; Binary compounds; Aluminium; Nanostructures; Coverage rate; Gallium nitride; Anodizing; Indium Nitrides; Indium nitride; Anodic oxide; Porosity; III-V semiconductors
• ISSN: 0947-8396; 1432-0630
• DOI: 10.1007/s00339-012-7410-8

Anodic aluminum oxide (AAO) films with different porosities were fabricated on the surfaces of InGaN/GaN multiple quantum wells (MQWs). We measured the photoluminescence spectra of these samples and then calculated the light extraction enhancement factors ( E ). It was found that the light extraction of the MQWs with the AAO films has been greatly enhanced compared to the area without AAO coverage. The maximum value of E reaches 3.5 at a certain wavelength and 2.29 in the integral intensity. The increase of E with the decrease of the porosities demonstrates that the nano-hole structure in the AAO films plays an important role in enhancing the light extraction efficiency.