Abstract
Abstract
Graphene is grown directly on c-, a-, m-, and r-plane sapphire substrates by CVD, and their structures and electrical properties are compared. The obtained graphene is always polycrystalline, but the grain size is dependent on the sapphire surface orientation. The largest and smallest grains respectively appear on the m- and c-planes, and the graphene grown on the a- and r-planes has intermediate grain sizes. The carrier mobility is the largest for the graphene grown on the m-plane, indicating that the grain boundaries make a significant impact on the carrier transport as scattering centers. Nevertheless, the RT Hall effect mobility measured for the mm-sized m-plane samples reaches 7000 cm2 V−1 s−1. m-plane sapphire is promising as an insulating substrate for direct graphene growth.
Funder
Japan Society for the Promotion of Science
Subject
General Physics and Astronomy,General Engineering