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Computational study of the structural, electronic and optical properties of M2N2(NH): M = C, Si, Ge, Sn
被引:13
作者:
Manyali, George S.
[1
]
Warmbier, Robert
Quandt, Alexander
机构:
[1] Univ Witwatersrand, Sch Phys, ZA-2050 Johannesburg, South Africa
基金:
新加坡国家研究基金会;
关键词:
DFT;
Semiconductors;
Dielectric constant;
Mechanical properties;
GENERALIZED GRADIENT APPROXIMATION;
NITRIDE IMIDE;
AB-INITIO;
SOLIDS;
C3N4;
D O I:
10.1016/j.commatsci.2013.07.038
中图分类号:
T [工业技术];
学科分类号:
08 ;
摘要:
We present the first principles calculations of electronic, structural and optical properties of Ge2N2(NH) and Sn2N2(NH), isostructural with Si2N2(NH) and C2N2(NH). The M2N2(NH) compounds, where M = Si or C or Ge or Sn, crystallise into base-centered orthorhombic (BCO) structure, space group Cmc2(1). Our results indicate that Ge2N2(NH) and Sn2N2(NH) are stable compounds, satisfying mechanical stability tests and lack imaginary phonon modes. In addition, the two compounds have fairly smaller bulk moduli compared to Si2N2(NH) and C2N2(NH). Ge2N2(NH) has a direct band gap of 2.66 eV in DFT-GGA while Sn2N2(NH) posses a small indirect band gap of 1.05 eV. We also analyse the dielectric behaviours of the M2N2(NH) compounds within infrared (IR), visible and ultraviolet (UV) regimes in which Ge2N2(NH) and Sn2N2(NH) show remarkable characteristics. (C) 2013 Elsevier B.V. All rights reserved.
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页码:710 / 714
页数:5
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