Computational study of the structural, electronic and optical properties of M2N2(NH): M = C, Si, Ge, Sn

George S. Manyali; Robert Warmbier; Alexander Quandt

doi:10.1016/j.commatsci.2013.07.038

Computational study of the structural, electronic and optical properties of M₂N₂(NH): M = C, Si, Ge, Sn

George S. Manyali, Robert Warmbier, Alexander Quandt

University of the Witwatersrand

Research output: Contribution to journal › Article › peer-review

11 Citations (Scopus)

Abstract

We present the first principles calculations of electronic, structural and optical properties of Ge₂N₂(NH) and Sn₂N ₂(NH), isostructural with Si₂N₂(NH) and C ₂N₂(NH). The M₂N₂(NH) compounds, where M = Si or C or Ge or Sn, crystallise into base-centered orthorhombic (BCO) structure, space group Cmc2₁. Our results indicate that Ge ₂N₂(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). Ge ₂N₂(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.

Original language	English
Pages (from-to)	710-714
Number of pages	5
Journal	Computational Materials Science
Volume	79
DOIs	https://doi.org/10.1016/j.commatsci.2013.07.038
Publication status	Published - 2013
Externally published	Yes

Keywords

DFT
Dielectric constant
Mechanical properties
Semiconductors

ASJC Scopus subject areas

General Computer Science
General Chemistry
General Materials Science
Mechanics of Materials
General Physics and Astronomy
Computational Mathematics

Access to Document

10.1016/j.commatsci.2013.07.038

Cite this

@article{797e1f5b133548a7a622bf79dbdb944e,

title = "Computational study of the structural, electronic and optical properties of M2N2(NH): M = C, Si, Ge, Sn",

abstract = "We present the first principles calculations of electronic, structural and optical properties of Ge2N2(NH) and Sn2N 2(NH), isostructural with Si2N2(NH) and C 2N2(NH). The M2N2(NH) compounds, where M = Si or C or Ge or Sn, crystallise into base-centered orthorhombic (BCO) structure, space group Cmc21. Our results indicate that Ge 2N2(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). Ge 2N2(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.",

keywords = "DFT, Dielectric constant, Mechanical properties, Semiconductors",

author = "Manyali, {George S.} and Robert Warmbier and Alexander Quandt",

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doi = "10.1016/j.commatsci.2013.07.038",

language = "English",

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pages = "710--714",

journal = "Computational Materials Science",

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TY - JOUR

T1 - Computational study of the structural, electronic and optical properties of M2N2(NH)

T2 - M = C, Si, Ge, Sn

AU - Manyali, George S.

AU - Warmbier, Robert

AU - Quandt, Alexander

PY - 2013

Y1 - 2013

N2 - We present the first principles calculations of electronic, structural and optical properties of Ge2N2(NH) and Sn2N 2(NH), isostructural with Si2N2(NH) and C 2N2(NH). The M2N2(NH) compounds, where M = Si or C or Ge or Sn, crystallise into base-centered orthorhombic (BCO) structure, space group Cmc21. Our results indicate that Ge 2N2(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). Ge 2N2(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.

AB - We present the first principles calculations of electronic, structural and optical properties of Ge2N2(NH) and Sn2N 2(NH), isostructural with Si2N2(NH) and C 2N2(NH). The M2N2(NH) compounds, where M = Si or C or Ge or Sn, crystallise into base-centered orthorhombic (BCO) structure, space group Cmc21. Our results indicate that Ge 2N2(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). Ge 2N2(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.

KW - DFT

KW - Dielectric constant

KW - Mechanical properties

KW - Semiconductors

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DO - 10.1016/j.commatsci.2013.07.038

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