Electronic and optical properties of hydrogenated group-IV multilayer materials.
Electronic and optical properties of hydrogenated group-IV multilayer materials.
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DOI：
10.1039/c7cp08471d
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发表时间：
2018-03
期刊：
影响因子：
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通讯作者：
R. B. Pontes;Rosana Rabelo Mançano;Rafael da Silva;L. Cotica;R. Miwa;J. E. Padilha
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文献类型：
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作者：
R. B. Pontes;Rosana Rabelo Mançano;Rafael da Silva;L. Cotica;R. Miwa;J. E. Padilha
Hydrogenated group-IV layered materials are semiconducting forms of silicene, germanene and stanene. We systematically studied the evolution of the structural, electronic and optical properties of these 2D materials as a function of the number of layers. We verify that the exfoliation energy increases upon the increase of the atomic number (Si → Sn) of the group-IV material. We show that silicane, independent of the number of layers, is an indirect band gap (Γ-M) material. This behavior is different from both germanane and stanane, which are direct band gap (Γ point) semiconductors. The calculated optical spectra show, for all systems, a red shift in the absorption edges and an enhanced absorption of the visible light for the in-plane (α‖) component upon the increase in the number of layers and, also as a function of the increasing atomic number. Our findings also indicate that: (i) (XH2)m(YH2)n vdW heterostructures will always present a type-I band alignment for X = Si and Y = Ge or Sn, whereas (ii) for X = Ge and Y = Sn, the band alignment can be tuned (type-I ↔ type-II) by the number of layers (m,n).
