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Structural and Optical Properties of GaN Nanowires Formed on Si(111)
Appl. Sci. Converg. Technol. 2018;27:95-99
Published online September 30, 2018;  https://doi.org/10.5757/ASCT.2018.27.5.95
© 2018 The Korean Vacuum Society.

Sangmoon Hana, Ilgyu Choia, Jihoon Songa, Cheul-Ro Leea, Il-Wook Chob, Mee-Yi Ryub, and Jin Soo Kima,*

aDepartment of Electronic and Information Materials Engineering, Division of Advanced Materials Engineering, and Research Center of Advanced Materials Development, Chonbuk National University, Jeonju 54896, South Korea
bDepartment of Physics, Kangwon National University, Chuncheon 24341, South Korea
Correspondence to: E-mail: kjinsoo@jbnu.ac.kr
Received July 16, 2018; Revised September 20, 2018; Accepted September 21, 2018.
Abstract
We discuss the structural and optical characteristics of GaN nanowires (NWs) grown on Si(111) substrates by a plasma-assisted molecular-beam epitaxy. The GaN NWs with high crystal quality were formed by adopting a new growth approach, so called Ga pre-deposition (GaPD) method. In the GaPD, only Ga was supplied without nitrogen flux on a SiN/Si surface, resulting in the formation of Ga droplets. The Ga droplets were used as initial nucleation sites for the growth of GaN NWs. The GaN NWs with the average heights of 60.10 to 214.62 nm obtained by increasing growth time. The hexagonal-shaped top surfaces and facets were observed from the field-emission electron microscope images of GaN NWs, indicating that the NWs have the wurtzite (WZ) crystal structure. Strong peaks of GaN (0002) corresponding to WZ structures were also observed from double crystal x-ray diffraction rocking curves of the NW samples. At room temperature, free-exciton emissions were observed from GaN NWs with narrow linewidth broadenings, indicating to the formation of high-quality NWs.
Keywords : Plasma-assisted molecular-beam epitaxy, GaN, Nanowires, Si substrate


September 2018, 27 (5)