中文摘要：

基于含时密度泛函理论,研究线性稠环芳烃连接的石墨烯量子点的等离激元激发.在低能共振区,体系存在2种不同的激发模式.一种激发模式主要位于可见光及近红外光谱区,参与该激发模式的离域化π电子在整个体系中运动;随着线性稠环芳烃链长度的增加,该激发模式发生红移,并且激发强度增大.另一种激发模式主要位于5 e V附近,参与该激发模式的π电子在一个石墨烯量子点中运动,该激发模式基本上不受线性稠环芳烃链长度的影响.此外,线性稠环芳烃连接的石墨烯量子点在近红外光谱区的等离激元激发还依赖于石墨烯量子点的形状.

英文摘要：

Plasmon excitations in graphene quantum dots connected by linear polycyclic aromatic hydrocarbons are investigated by time-dependent density functional theory（ TDDFT）. In lower-energy resonance zone,there are two different excitation modes in the system. One excitation mode is mainly located in the visible and near-infrared spectrum region. The delocalized π electron involved in this excitation mode can move in the whole system. With the increase of the linear polycyclic aromatic hydrocarbons chain length,this excitation mode is red-shifted,and the excitation intensity increases. The other excitation mode is mainly located around 5 e V. The delocalized π electron involved in this excitation mode only move in one graphene quantum dot. And this excitation mode is essentially unaffected by the linear polycyclic aromatic hydrocarbons chain length. Moreover,in the near-infrared spectral region,plasmon excitations in graphene quantum dots connected by linear polycyclic aromatic hydrocarbons also depends on the shape of the graphene quantum dots.