物理学报2011，Vol.60Issue(4)：570-575,6.
石墨烯量子点的磁性及激发态性质
Magnetic properties and excited states of the graphene quantum dots
摘要
Abstract
We use the density functional theory B3LYP/6-31G(d) to study the graphene quantum dots with zigzag edges. The result shows that the ground states of different size graphene quantum dots are all ferromagnetic spin-triplet states. The magnetic properties orignate both from the boundary carbon atom occuping protruding position, and from the carbon atom with unpaired electron. On the whole, the energy gap of other structures decreases with the increase of the number of benzene rings as excepted for the structure of 6b, and the system energy gap decreases significantly by the added charges.In addition, using time-dependent density functional theory ( TD-DFT), the excited states of the triangular structure composed of six carbon rings which have an energy gap is 3.83 eV are calculated, and the results show that the 17th excited state has the greatest excitation strength, the excitation energy is 3.93 eV, corresponding to a wavelength of 315.8 nm, close to experimental result.关键词
石墨烯量子点/磁性/能隙/激发态Key words
graphene quantum dots/ magnetism/ energy gap/ excited state引用本文复制引用
高双红,任兆玉,郭平,郑继明,杜恭贺,万丽娟,郑琳琳..石墨烯量子点的磁性及激发态性质[J].物理学报,2011,60(4):570-575,6.基金项目
国家重点基础研究发展计划(批准号:2009CB626611),国家自然科学基金(批准号:10974152),国家自然科学基金青年科学基金(批准号:10904123),西北大学研究生科研实验类项目(批准号:09YSY13)资助的课题. （批准号:2009CB626611）
