Li Li-Min, Pan Hai-Bin, Yan Wen-Sheng, Xu Peng-Shou, Wei Shi-Qiang, Chen Xiu-Fang, Xu Xian-Gang, Kang Chao-Yang, Tang Jun. Preparation of graphene on different-polarity 6H-SiC substrates and the study of their electronic structuresJ. Acta Physica Sinica, 2011, 60(4): 047302. DOI: 10.7498/aps.60.047302