First-principles multiscale modelling of charged adsorbates on doped graphene
First-principles multiscale modelling of charged adsorbates on doped graphene
复制标题
DOI：
10.1088/2053-1583/aa6811
复制
发表时间：
2017-06-01
期刊：
影响因子：
5.5
通讯作者：
Lischner, Johannes
中科院分区：
文献类型：
--
作者：
Corsetti, Fabiano;Mostofi, Arash A.;Lischner, Johannes
吸附的原子和分子在控制和调节二维（2D）材料的功能特性方面起着重要的作用。从理论上理解和预测这一过程是具有挑战性的，因为需要捕捉本地化学和远程筛选响应之间的复杂相互作用。为了解决这个问题，我们提出了一个第一性原理的多尺度方法，结合线性标度密度泛函理论，连续屏蔽理论和大规模的紧束缚模拟到一个无缝的无参数理论的吸附在二维材料。我们应用这种方法来研究掺杂石墨烯的电子结构与一个单一的钙（Ca）吸附原子，并发现，钙原子作为库仑杂质，修改石墨烯局域态密度（LDOS）在其附近的几个纳米的距离内。我们还观察到一个重要的掺杂依赖性的石墨烯LDOS附近的钙原子，这使得深入了解石墨烯中的电子屏蔽。我们的多尺度框架开辟了调查复杂的介观吸附质配置的二维材料相关的真实的设备的可能性。
Adsorbed atoms and molecules play an important role in controlling and tuning the functional properties of two-dimensional (2D) materials. Understanding and predicting this process from theory is challenging because of the need to capture the complex interplay between the local chemistry and the long-range screening response. To address this problem, we present a first-principles multiscale approach that combines linear-scaling density-functional theory, continuum screening theory and large-scale tight-binding simulations into a seamless parameter-free theory of adsorbates on 2D materials. We apply this method to investigate the electronic structure of doped graphene with a single calcium (Ca) adatom and find that the Ca atom acts as a Coulomb impurity which modifies the graphene local density of states (LDOS) within a distance of several nanometres in its vicinity. We also observe an important doping dependence of the graphene LDOS near the Ca atom, which gives insights into electronic screening in graphene. Our multiscale framework opens up the possibility of investigating complex mesoscale adsorbate configurations on 2D materials relevant to real devices.