Ex) Article Title, Author, Keywords
New Physics: Sae Mulli 2017; 67: 896-901
Published online July 31, 2017 https://doi.org/10.3938/NPSM.67.896
Copyright © New Physics: Sae Mulli.
Dae-Jin KIM1, Ki-Soo LIM*1, Ik-Bu SOHN2
This is an open-access article distributed under the terms of the Creative Commons Attribution Non-Commercial License (http://creativecommons.org/licenses/by-nc/3.0/) which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited.
We report self-organized nanogratings formed on the surfaces of ZnO and GaN crystals by scanning a focused femtosecond laser beam at 800 nm with a repetition rate of 1 kHz. The period of the grating structure was about 600 nm on the GaN surface and about 200 nm on the ZnO surface and increased with increasing scan speed and laser pulse energy. The grating was oriented perpendicular to the direction of the linear laser's polarization. The nanogratings on the GaN surface showed metal-like characteristics due to the high plasma density while those on the ZnO surface showed dielectric-like characteristics. This could be due to the electron densities for the two surfaces being very different as a result of differences in their multiphoton absorption coefficients and internal defects, even though their band gaps were almost the same.
Keywords: GaN, ZnO, Femtosecond laser, Nanograting, Surface plasmon polariton