Article

Electronic and related properties of crystalline semiconducting iron disilicide

Belarusian State University of Informatics and Radioelectronics, P. Browka 6, 220027 Minsk, Belarus
Journal of Applied Physics (Impact Factor: 2.19). 06/1996; 79(10):7708 - 7712. DOI: 10.1063/1.362436
Source: IEEE Xplore

ABSTRACT Band structure calculations for β‐FeSi 2 have been performed by the linear muffin‐tin orbital method within the local density approximation scheme including exchange and correlation effects. A detailed analysis of the conduction and valence band structure around high‐symmetry points has shown the existence of a quasidirect band gap structure in the material. It is experimentally confirmed that between the threshold energy of optical interband transition of 0.73 eV and the first direct gap transition with appreciable oscillator strength at about 0.87 eV there is a region in which direct transition of low oscillator strength and indirect transitions overlap. That explains the tricky behavior of β‐FeSi 2 in experimental investigations demonstrating it to be either a direct or indirect gap semiconductor. © 1996 American Institute of Physics.

0 Followers
 · 
53 Views
  • [Show abstract] [Hide abstract]
    ABSTRACT: The geometrical and electronic structures of β-Fe(Si 2- xGe x) ternaries were investigated using first principles pseudopotential calculations based on generalized gradient approximation density function theory. These compounds are indirect-bandgap semiconductors with theoretical energy band gaps ranging from 0.51 to 0.79 eV. Substitution of Ge for Si in β-FeSi 2 leads to a reduction of the gap width and an increase in the volume of the unit cell with almost the same shape of the last valence band and the first conduction band but for the Y point. The analyses of bond overlap population and Mulliken population revealed that the covalency between Fe and Si atoms are strengthened by increasing Ge content and that the electron transfer occurs from Ge to Fe or Si.
    Journal of Solid State Chemistry 11/2002; 169(1):19-23. DOI:10.1016/S0022-4596(02)00004-X · 2.20 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: The β-FeSi2 thin film has been applied in the research field of the solar cell, and the thickness of β-FeSi2 absorption layer was chosen through the experiments. However, Up to now neither the optimal thickness of β-FeSi2 absorption layer nor the relationship between the thickness of β-FeSi2 absorption layer and the solar photo wavelength has been theoretically studied. In this paper, the relationship between the thickness of the absorption layer of β-FeSi2 thin film solar cell and the solar photo wavelength is calculated and analyzed by theory. The results show that the thickness of the absorption layer of β-FeSi2 is at least 200 nm when the optical absorption efficiency of the solar energy reaches 90%, and that the optimal thickness range is from 200 nm to 250 nm, and that the optimal wavelength of the photon absorbed by β-FeSi2 thin film solar cell is from 0.46 μm–0.6 μm. Furthermore, two formulas are put forward to indicate the relationship between the thickness of the absorption layer of β-FeSi2 thin film solar cell and the solar photo wavelength. The thickness of the absorption layer of β-FeSi2 thin film solar cell increases linearly with the solar photo wavelength within the optimal photo wavelength. The formulas provide a reliable theoretical basis of determining the thickness of the β-FeSi2 thin film in the solar cell.
    Chinese Journal of Mechanical Engineering 03/2012; 25(2). DOI:10.3901/CJME.2012.02.315 · 0.45 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Ternary Fe(Os)Si(2) alloys, a novel semiconducting opto-electronic material with a tuneable direct band gap property, was designed by energy-band engineering. The electronic structures of FeSi(2), OsSi(2) and (FeOs)Si(2) were theoretically calculated using the density functional theory (DFT) method. The thin films were fabricated by magnetic co-sputtering deposition, so as to substitute the Fe sublattice sites by Os. X-ray diffraction, energy dispersion X-ray spectrometry and optical absorption spectroscopy were used to characterize the structural properties of the thin films. Experimental results showed that all the Fe(1-x)Os(x)Si(2) films have a direct band gap property. The strongest optical absorption was obtained when x is equal to 0.5, which is consistent with the theoretical prediction. (C) 2010 Published by Elsevier B.V.
    Physics Procedia 01/2011; 11:75-78. DOI:10.1016/j.phpro.2011.01.016