Optical and electrical characteristics of nitride nanorod array with Ti-mask selective-area growth by plasma-assisted molecular beam epitaxy
C. W. Chang1*, S. S. Guo1, C. Y. Chang1, L. W. Tu1
1Department of Physics and Center for Nanoscience and Nanotechnology, National Sun Yat-Sen University, Kaohsiung, Taiwan
* presenting author:Ching-Wen Chang, email:changchingwen0921262805@gmail.com
The nitride nanorod regularly arranged array is fabricated using GaN template as the substrate by employing the plasma-assisted molecular beam epitaxy technique. III-V nitride hexagonal structure material is difficult to find a low-cost substrate with matching lattice constant and thermal expansion coefficient. Therefore, high quality nitride thin films are hard to obtain. Due to the small bottom contact area of a nanorod with the substrate, the nanorod structure can reduce the defects such as dislocations and increase the crystal quality. Tessarek et al. observed GaN nanorods of a diameter larger than 500 nm with dislocations and 200 nm without dislocations by transmission electron microscopy measurements [1]. Furthermore, nanorod has a huge capacity on photovoltaic applications because of the improvement in light trapping for enhanced photon absorption. This report, nano-sphere lithography [2] will be used to fabricate the holed titanium substrate [3]. I-V curves with a light effect are observed at room temperature to show the electrical characteristics and extensive optical analyses of nanorod array are performed.

[1] C. Tessarek et al., Journal of Applied Physics 114, 144304 (2013).
[2] S. Astilean, Romanian Reports in Physics 56, 340 (2004).
[3] K. Kishino et al., Journal of Crystal Growth 311, 2063 (2009).

Keywords: Nitride, Nanorod, PA-MBE