Tunable Band Gap in Hydrogenated Quasi-Free-standing Graphene
Tunable Band Gap in Hydrogenated Quasi-Free-standing Graphene
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DOI：
10.1021/nl101066m
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发表时间：
2010-09-01
期刊：
影响因子：
10.8
通讯作者：
Grueneis, A.
中科院分区：
文献类型：
--
作者：
Haberer, D.;Vyalikh, D. V.;Grueneis, A.
我们通过角分辨光发射光谱显示，氢化可以诱导金上准独立单层石墨烯的可调间隙。间隙的大小可以通过氢气负载来控制，当氢气覆盖率为8%时，间隙的大小可以达到1.0 eV。通过x射线光电子能谱和x射线吸收观察到sp(2)到sp(3)在化学键中的局部再杂化，从而可以测定化学吸收氢的量。在不破坏石墨烯的情况下，氢诱导的间隙形成是完全可逆的。计算的氢负载相关的核能级结合能和石墨烯的光谱函数与光电发射实验非常吻合。石墨烯的氢化可以获得可调的电子和光学特性，从而为研究碳材料中的储氢提供了一个模型系统。
We show by angle-resolved photoemission spectroscopy that a tunable gap in quasi-free-standing monolayer graphene on Au can be induced by hydrogenation. The size of the gap can be controlled via hydrogen loading and reaches similar to 1.0 eV for a hydrogen coverage of 8%. The local rehybridization from sp(2) to sp(3) in the chemical bonding is observed by X-ray photoelectron spectroscopy and X-ray absorption and allows for a determination of the amount of chemisorbed hydrogen. The hydrogen induced gap formation is completely reversible by annealing without damaging the graphene. Calculations of the hydrogen loading dependent core level binding energies and the spectral function of graphene are in excellent agreement with photoemission experiments. Hydrogenation of graphene gives access to tunable electronic and optical properties and thereby provides a model system to study hydrogen storage in carbon materials.