单层1T-VS_(2)的电子结构和量子电容性质研究  

Electronic Structures and Quantum Capacitance of Monolayer 1T-VS_(2)

作　　者：李雯婷 王维华 Li Wenting;Wang Weihua(Department of Electronic Science and Engineering,College of Electronic Information and Optical Engineering,Nankai University,Tianjin 300350,China)

机构地区：[1]南开大学电子信息与光学工程学院,电子科学与工程系,天津300350

出　　处：《南开大学学报（自然科学版）》2024年第1期73-78,共6页Acta Scientiarum Naturalium Universitatis Nankaiensis

基　　金：国家自然科学基金(11874223,51871121)。

摘　　要：以石墨烯为代表的低维材料由于费米能级附近有限的态密度,导致量子电容较低,限制了其作为电极材料的超级电容器双电层电容的提升.采用基于密度泛函理论的第一性原理计算方法,以1T-VS_(2)为例,研究具有类石墨烯结构的准二维材料的量子电容的微观机理及其性能调控.研究结果表明,铁磁性的本征和含V空位缺陷的1T-VS_(2)在零偏压处的量子电容为~300μF/cm^(2),远高于石墨烯.此外,含有V空位缺陷体系在负偏压区的高量子电容区间更加扩展,可以匹配更宽工作电压窗口的电解质材料,有利于提高能量密度.Low-dimensional materials represented by graphene display low quantum capacitance due to the limited density of states near the Fermi level,which sets limitation for the improvement of the electrochemical double layer capacitance in supercapacitors.Thus,it is urgent to explore the microscopic mechanism and further to modulate the quantum capacitance performance in graphene-like quasi-two-dimensional materials.The first principles calculations based on density functional theory were adopted to investigate the system of 1T-VS_2.The results show that the quantum capacitance of the ferromagnetic pristine 1T-VS_(2) and 1T-VS_(2) with individual V vacancy is~300μF/cm^(2) near 0.0 V,which is much higher than graphene.In addition,the high quantum capacitance range of 1T-VS_(2) with V vacancy is more extended in the negative bias,implying that 1T-VS_(2) with V vacancy could match the electrolytes with wide working voltage window and the energy density could be improved.

关 键 词：1T-VS_(2) 电子结构 量子电容 本征缺陷 第一性原理计算 

分 类 号：O469[理学—凝聚态物理]