Effect of edge-hydrogen passivation and nanometer size on the electronic properties of phagraphene ribbons

详细信息    查看全文

• 作者：Yunjin Liu ; Zheng Chen ; Lijia Tong ; Jing Zhang ; Dongqiang Sun
• 关键词：Phagraphene nanoribbons (PHAGNRs) ; First-principles ; Structure ; Passivation ; Electronic properties ; Nanometer size
• 刊名：Computational Materials Science
• 出版年：2016
• 出版时间：May 2016
• 年：2016
• 卷：117
• 期：Complete
• 页码：279-285
• 全文大小：2346 K

文摘

Based on a first-principles approach, the structures and electronic properties are investigated for both pure zigzag phagraphene nanoribbons (ZPHAGNRs) and mixture phagraphene nanoribbons (MPAHGNRs) terminated edges with hydrogen atoms or bare edges. There are many differences between bare and passivated phagraphene nanoribbons (PHAGNRs) in structure parameters after geometry optimization, although they still keep the two-dimensional plane structures. The edge states and quantum confined effect play crucial roles in the electronic properties for PHAGNRs. Our results show that ZPHAGNRs and bare MPHAGNRs are metallic, while the MPHAGNRs terminated edges with hydrogen atoms with direct band gap arise from quantum confined effect. The electronic properties of MPHAGNRs with passivated by hydrogen are further probed with the variation of width (N_M = 4–21). Our works indicate that all of the calculated H-MPHAGNRs are direct band gap, and 4-H-MPHAGNR has the largest band gap is 1.02 eV. Generally, the band gaps decreased with respect to the ribbon widths increasing. However, the variation in band gaps exhibits three distinct family behaviors. The band gap sequence is gap_3q > gap_3q+1 > gap_3q+2.