Share Email Print

Proceedings Paper

Fabrication and lasing characteristics of GaN nanopillars
Format Member Price Non-Member Price
PDF $14.40 $18.00
cover GOOD NEWS! Your organization subscribes to the SPIE Digital Library. You may be able to download this paper for free. Check Access

Paper Abstract

We report the fabrication of GaN nanopillars and their laser action characteristics under optical pumping measurement. The nanopillars were fabricated from a GaN epitaxial wafer by self-assembled Ni nanomasked etching, followed by epitaxial regrowth to form crystalline facets on the etched nanopillars. The regrowth process is intended to reduce surface defects created during ICP-RIE etching. The density of etched GaN nanopillars is about 8.5x108/cm2 and the diameter and height of GaN nanopillars are about 250 nm and 650 nm, respectively. The as grown GaN nanopillars exhibit a random distribution with hexagonal pillar geometry. The sample is optically excited by frequency tripled Nd:YAG pulsed laser. The Gaussian waist of pumping spot is 1.8 um. At low pumping intensity, the emission has a broad spontaneous emission spectrum with maximum at 363 nm. As pump intensity increases, a narrow peak at 363 nm emerges quickly from the broad spontaneous emission back ground. The lasing action occurs at threshold pump power density of 122 MW/cm2. The emission linewidth decreases with pumping power across threshold and reaches a lowest value of about 0.38 nm above threshold. The excitation-power-dependent spectra show that the lasing wavelength has a slight blue shift as pump power increases. We remark that this is due the band filling of the increasing excited carrier density.

Paper Details

Date Published: 3 March 2011
PDF: 6 pages
Proc. SPIE 7939, Gallium Nitride Materials and Devices VI, 79391T (3 March 2011); doi: 10.1117/12.874151
Show Author Affiliations
Ming-Hua Lo, National Chiao Tung Univ. (Taiwan)
Academia Sinica (Taiwan)
Yuh-Jen Cheng, National Chiao Tung Univ. (Taiwan)
Academia Sinica (Taiwan)
Hao-Chung Kuo, National Chiao Tung Univ. (Taiwan)
Shing-Chung Wang, National Chiao Tung Univ. (Taiwan)

Published in SPIE Proceedings Vol. 7939:
Gallium Nitride Materials and Devices VI
Jen-Inn Chyi; Yasushi Nanishi; Hadis Morkoç; Joachim Piprek; Euijoon Yoon, Editor(s)

© SPIE. Terms of Use
Back to Top