吸附对石墨烯量子点电子结构和光学性质的影响  

Electronic Structure and Optical Properties in Graphene Quantum Dots Under Adsorption

作　　者：田梦园 陈桥[1] TIAN Mengyuan;CHEN Qiao(School of Computational Science and Electronics,Hunan Institute of Engineering,Xiangtan 411104,China)

机构地区：[1]湖南工程学院计算科学与电子学院,湘潭411104

出　　处：《湖南工程学院学报（自然科学版）》2022年第1期67-73,共7页Journal of Hunan Institute of Engineering(Natural Science Edition)

基　　金：湖南省自然科学基金资助项目(2020JJ4240).

摘　　要：采用紧束缚近似方法研究了吸附对锯齿状六边形石墨烯量子点电子结构和光学性质的影响.研究表明,在吸附浓度为100%时,零能附近存在体态,边缘态被排斥到远离零能区域,且打开量子点能隙.进一步研究表明,零能附近的体态完全位于吸附原子上,边缘态则同时位于吸附原子和碳原子上.在量子点尺寸较小时,由于吸附原子的作用,导致量子点的能隙被关闭,但随着吸附原子与碳原子之间的耦合强度增强,能隙又被打开.研究发现量子点的光吸收峰会随着吸附浓度的增强而发生蓝移.By using the tight-binding(TB)method,the electronic structure and optical properties of the zig-zag hexagonal graphene quantum dots(ZHGQDs)with adsorption are investigated.The results indicate that when the quantum dots is fully covered by homogeneous adsorbates,the bulk states emerge around zero ener-gy,and the edge states are repelled to a position far away from zero energy.The bulk states near zero energy are completely located on the adsorbed atoms,while the edge states are located on both the adsorbed and car-bon atoms.When the size of the ZHGQDs is small,the energy gap of the quantum dots is closed due to the ac-tion of adsorbed atoms.However,the energy gap of the quantum dots reopens as the coupling strength be-tween the adsorbed and carbon atoms increases.The study shows that the optical absorption peaks occur blue shift as the strength of adsorption concentration increases.

关 键 词：石墨烯量子点 电子结构和光学性质 吸附 耦合强度 

分 类 号：O469[理学—凝聚态物理]