SiC衬底上外延石墨烯的氢插入及表征

Hydrogen Intercalation and Characterization of Epitaxial Graphene Grown on SiC Substrates

使用热解法在4H-SiC硅面制备出单层石墨烯,而后将石墨烯置于氢气气氛下退火,使氢插入到缓冲层与SiC衬底之间。利用X射线光电子能谱对氢插入后的化学键变化进行了表征。样品的碳1s能谱中碳元素由SiC衬底、石墨烯及缓冲层共同构成。对不同氢气退火温度下各组分的强度进行采集与分析,并分别与相应的拉曼光谱数据进行对比。结果表明,低于800℃退火温度会造成氢插入的不完全,但当退火温度超过1200℃后,插入的氢将被释放。为获得较优的氢插入效果,需要选择1000℃左右的氢气退火温度。

Monolayer graphene was prepared by thermal decomposition of 4H-SiC substrates on the Siterminated face,subsequent hydrogen intercalation between buffer layer and substrate was achieved by annealing graphene in molecular hydrogen atmosphere. X-ray photoelectron spectroscopy was used to analyze the chemical bonding states of graphene after hydrogen intercalation. The C 1s core-level was resolved into carbon from bulk SiC,carbon from graphene and carbon from buffer layer. The intensity of each component under different hydrogen intercalation temperture was recorded and analyzed. Compared with Raman spectroscopy,the results show that hydrogen intercalation was incomplete below 800 ℃ while hydrogen desorbed above 1200 ℃. The optimum temperature of around 1000 ℃ should be taken to obtain better hydrogen intercalation effect.