Vacuum annealing formation of graphene on diamond C(111) surfaces studied by real-time photoelectron spectroscopy

真空アニールによるダイヤモンドC(111)表面でのグラフェン形成のリアルタイム光電子分光観察

小川 修一*; 山田 貴壽*; 吉越 章隆 ; 石塚 眞治*; 渡辺 大輝*; 長谷川 雅考*; 寺岡 有殿; 高桑 雄二*

Ogawa, Shuichi*; Yamada, Takatoshi*; Yoshigoe, Akitaka; Ishizuka, Shinji*; Watanabe, Daiki*; Hasegawa, Masataka*; Teraoka, Yuden; Takakuwa, Yuji*

Diamond has been attracted as a substrate for graphene growth. It has been reported the graphitization of diamond C(111) surface by annealing in vacuum. The aim of this study is to identify the sp-bonded carbon layer and to clarify the formation mechanism of a graphene layer on the diamond C(111) surface (GOD). In order to achieve this aim, real-time photoemission spectroscopy using synchrotron radiation (SR-XPS) and ultraviolet He I resonance line (UPS) was employed for investigation of vacuum annealing processes of C(111) surface. Graphitization of diamond surface is clearly observed from the analysis of C 1s energy loss spectra. The sp component comes out as a 21 reconstruction structure component goes in by annealing. This is also confirmed by UPS measurement. In the UPS spectra, the surface state peaks derived from dangling bonds can be clearly observed at low temperature. Based on these results, formation processes of GOD is proposed.