Properties of graphene deposited on GaN nanowires: influence of nanowire roughness, self-induced nanogating and defects

Beilstein Journal of Nanotechnology

article

Jakub Kierdaszuk¹  Piotr Kaźmierczak¹  Justyna Grzonka²  Aleksandra Krajewska³  Aleksandra Przewłoka³  Wawrzyniec Kaszub³  Zbigniew R. Zytkiewicz⁶  Marta Sobanska⁶  Maria Kamińska¹  Andrzej Wysmołek¹  Aneta Drabińska¹ 

[1] Faculty of Physics, University of Warsaw;University of Cadiz, Department of Material Science and Metallurgy Engineering and Inorganic Chemistry;Łukasiewicz - Institute of Microelectronics and Photonics;CENTERA Laboratories, Institute of High Pressure Physics PAS;Institute of Optoelectronics, Military University of Technology;Institute of Physics, Polish Academy of Sciences

关键词: carrier concentration;    gallium nitride;    graphene;    nanowires;    Ramanspectroscopy;    scattering on defects;    strain;   

DOI  :  10.3762/bjnano.12.47

学科分类：环境监测和分析

来源: Beilstein - Institut zur Foerderung der Chemischen Wissenschaften

【 摘 要 】

We present detailed Raman studies of graphene deposited on gallium nitride nanowires with different variations in height. Ourresults indicate that different density and height of nanowires impact graphene properties such as roughness, strain, and carrier concentration as well as density and type of induced defects. Tracing the manifestation of those interactions is important for the application of novel heterostructures. A detailed analysis of Raman spectra of graphene deposited on different nanowire substrates showsthat bigger differences in nanowires height increase graphene strain, while a higher number of nanowires in contact with graphenelocally reduces the strain. Moreover, the value of graphene carrier concentration is found to be correlated with the density of nanowires in contact with graphene. The lowest concentration of defects is observed for graphene deposited on nanowires with thelowest density. The contact between graphene and densely arranged nanowires leads to a large density of vacancies. On the otherhand, grain boundaries are the main type of defects in graphene on rarely distributed nanowires. Our results also show modificationof graphene carrier concentration and strain by different types of defects present in graphene. Therefore, the nanowire substrate ispromising not only for strain and carrier concentration engineering but also for defect engineering.

【 授权许可】

CC BY