Big Bandgap in Highly Reduced Graphene Oxides

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• 作者：Ke-Yan Lian ; Yong-Fei Ji ; Xiao-Fei Li ; Ming-Xing Jin ; Da-Jun Ding ; Yi Luo
• 刊名：The Journal of Physical Chemistry C
• 出版年：2013
• 出版时间：March 28, 2013
• 年：2013
• 卷：117
• 期：12
• 页码：6049-6054
• 全文大小：368K
• 年卷期：v.117,no.12(March 28, 2013)
• ISSN：1932-7455

文摘

It is generally believed that the bandgap of the graphene oxide is proportional to the concentration of the oxygen atoms and a highly reduced graphene oxide (rGO) without vacancy defects should be gapless. We show here from first principles calculations that the bandgap can be effectively opened even in low oxidation level with the absorption of oxygen atoms either symmetrically or asymmetrically. The properly arranged absorption can induce a bandgap up to 1.19 eV for a C/O ratio of 16/1 in a symmetric system and a bandgap up to 1.58 eV for a C/O ratio of 32/3 in an asymmetric system, at generalized gradient approximation (GGA) level. The hybridization between the in-plane p_xy orbitals of oxygen atoms and the out-of-plane p_z frontier orbital of graphene is responsible for the opening of the bandgap. This finding sheds new light on the bandgap engineering of graphene.