氢化石墨烯中Work Function的锯齿标度
A Saw-tooth Scaling of Work Function in Hydrogenated Graphene
摘要：
利用密度泛函理论对氢化石墨烯的功函数进行了锯齿标度研究。氢原子的位置和H/C比影响WF。通过对吸附两个氢原子的不同石墨烯结构的比较，发现石墨烯带的负电荷越少，WF越大。在不同的H/C比下，WF由两部分控制：石墨烯表面和氢基团。当比值小于0.5时，功函数对石墨烯的Mulliken电荷依赖性更强.氢原子越多，石墨烯表面的负性越大，导致功函数越小。当该比值大于0.5时，氢基团的影响不可忽略。当石墨烯的两侧氢原子数不同时，存在一个偶极子，使得电子从费米能级向真空能级的运动更加困难，因而WF大于两侧氢原子数相同时的WF。因此，功函数的缩放作用类似于取决于H/C比的锯齿。
英文摘要：
The saw-tooth scaling investigations of work functions (WF) in hydrogenated graphene are theoretically performed by density functional theory. The positions of hydrogen atoms and the H/C ratios affect WF. With the comparison of different graphene structures by adsorbed two hydrogen atoms, WF is larger with less negative charges of the graphene. With different H/C ratios, WF is controlled by two parts: the graphene surface and hydrogen groups. When the ratio is smaller than 0.5, the work func-tion is more dependent on the Mulliken charge of graphene. With more hydrogen atoms, the surface of graphene is more negative, resulting in a smaller work function. When the ratio is larger than 0.5, the effect of hydrogen groups cannot be ignored. When two sides of graphene have different numbers of hy-drogen atoms, a dipole exists, making the movement of electron from Fermi level to vacuum level more difficult, thus WF is larger than that with the same hydrogen atoms of each side. Therefore the scaling of work function acts like a saw-tooth dependent on H/C ratio.
机构、总结、中文摘要均由AI分析而来，可能存在错误，请以论文正文为准。
