摘要
Defects in silicon carbide （SIC） substrate are crucial to the properties of the epitaxial graphene （EG） grown on it. Here we report the effect of defects in SiC on the crystalline quality of EGs through comparative studies of the characteristics of the EGs grown on SiC （0001） substrates with different defect densities. It is found that EGs on high quality SiC possess regular steps on the surface of the SiC and there is no discernible D peak in its Raman spectrum. Conversely, the EG on the SiC with a high density of defects has a strong D peak, irregular stepped morphology and poor uniformity in graphene layer numbers. It is the defects in the SiC that are responsible for the irregular stepped morphology and lead to the small domain size in the EG.
Defects in silicon carbide （SIC） substrate are crucial to the properties of the epitaxial graphene （EG） grown on it. Here we report the effect of defects in SiC on the crystalline quality of EGs through comparative studies of the characteristics of the EGs grown on SiC （0001） substrates with different defect densities. It is found that EGs on high quality SiC possess regular steps on the surface of the SiC and there is no discernible D peak in its Raman spectrum. Conversely, the EG on the SiC with a high density of defects has a strong D peak, irregular stepped morphology and poor uniformity in graphene layer numbers. It is the defects in the SiC that are responsible for the irregular stepped morphology and lead to the small domain size in the EG.
基金
Project supported by the National Key Basic Research Program of China(Grant No.2011CB932700)
the Knowledge Innovation Project of the Chinese Academy of Sciences(Grant No.KJCX2-YW-W22)
the National Natural Science Foundation of China(Grant Nos.51272279 and 51072223)
