First Principles Investigation on the Structural, Electronic and Optical Properties of Amorphous Silica Glass

Abstract:

The structural, electronic, and optical properties of an amorphous SiO₂ (a-SiO₂) model is investigated by using first-principles calculation. Most research works used beta-cristobalite glass structure as a reference to amorphous silica structure. However, only the electronic properties were been presented without any link towards the optical properties. Here, we demonstrate simultaneous electronic and optical properties, which closely matched to a-SiO₂ properties by generating small sample of amorphous quartz glass. Using the Rietveld refinement, amorphous silica structure was generated and optimized using density functional theory in CASTEP computer code. A thorough analysis of the amorphous quartz structure obtained from different thermal treatment was carried out. The structure of amorphous silica was validated with previous theoretical and experimental works. It is shown that small sample of amorphous silica have similar structural, electronic and optical properties with a larger sample. The calculated optical and electronic properties from the a-SiO₂ glass match closely to previous theoretical and experimental data from others. The a-SiO₂ band gap of 5.853 eV is found to be smaller than the experimental value of ~9 eV. This is due to the underestimation and assumption made in DFT. However, the band gap value is in good agreement with the other theoretical works. Apart from the absorption edge at around 6.5 eV, the refractive index is 1.5 at 0eV. Therefore, this atomic structure can served as a reference model for future research works on amorphous structures.

• Periodical: Solid State Phenomena (Volume 268)
• Pages: 92-96
• DOI: https://doi.org/10.4028/www.scientific.net/SSP.268.92
• Online since: October 2017
• Authors: R.M. Nor*, S.N.M. Halim, Mohamad Fariz Mohamad Taib, M. Kamil Abd-Rahman
• Keywords: Amorphous Silica, CASTEP, Density Functional Theory (DFT), Glass

References

[1] Zallen, R., The physics of amorphous solids. 2008: John Wiley & Sons.

[2] Philipp, H., Optical properties of non-crystalline Si, SiO, SiOx and SiO2. Journal of Physics and Chemistry of Solids, 1971. 32(8): p.1935-(1945).

DOI: 10.1016/s0022-3697(71)80159-2

[3] Tu, Y., et al., Properties of a continuous-random-network model for amorphous systems. Physical Review Letters, 1998. 81(22): p.4899.

[4] Martínez, J., et al., Rietveld refinement of amorphous SiO2 prepared via sol–gel method. Materials letters, 2006. 60(29): pp.3526-3529.

DOI: 10.1016/j.matlet.2006.03.044

[5] He, H., et al., First-principles study of the structural, electronic, and optical properties of Ga2O3 in its monoclinic and hexagonal phases. Physical Review B, 2006. 74(19): p.195123.

[6] Hilden, L.R. and K.R. Morris, Physics of amorphous solids. Journal of pharmaceutical sciences, 2004. 93(1): pp.3-12.

[7] Keen, D.A., Refining disordered structural models using reverse Monte Carlo methods: Application to vitreous silica. Phase Transitions, 1997. 61(1-4): pp.109-124.

DOI: 10.1080/01411599708223732

[8] Mozzi, R. and B. Warren, The structure of vitreous silica. Journal of Applied Crystallography, 1969. 2(4): pp.164-172.

[9] DiStefano, T. and D. Eastman, The band edge of amorphous SiO2 by photoinjection and photoconductivity measurements. Solid State Communications, 1971. 9(24): pp.2259-2261.

DOI: 10.1016/0038-1098(71)90643-0

[10] Crowley, J.M., J. Tahir-Kheli, and W.A. Goddard III, Resolution of the Band Gap Prediction Problem for Materials Design. The journal of physical chemistry letters, 2016. 7(7): pp.1198-1203.

DOI: 10.1021/acs.jpclett.5b02870

[11] Martin‐Samos, L., et al., SiO2 in density functional theory and beyond. physica status solidi (b), 2011. 248(5): pp.1061-1066.

DOI: 10.1002/pssb.201046283

[12] Chimata, R., Optical Properties of Materials Calculated from First Principles Theory. (2010).

[13] Ghosh, G., Dispersion-equation coefficients for the refractive index and birefringence of calcite and quartz crystals. Optics communications, 1999. 163(1): pp.95-102.

DOI: 10.1016/s0030-4018(99)00091-7

[14] Tan, G., et al., Optical properties and London dispersion interaction of amorphous and crystalline SiO2 determined by vacuum ultraviolet spectroscopy and spectroscopic ellipsometry. Physical Review B, 2005. 72(20): p.205117.

DOI: 10.1103/physrevb.72.205117

[15] Tan, G.L., M.F. Lemon, and R.H. French, Optical properties and London dispersion forces of amorphous silica determined by vacuum ultraviolet spectroscopy and spectroscopic ellipsometry. Journal of the American Ceramic Society, 2003. 86(11): pp.1885-1892.

DOI: 10.1111/j.1151-2916.2003.tb03577.x

[16] Gupta, R.P., Electronic structure of crystalline and amorphous silicon dioxide. Physical Review B, 1985. 32(12): p.8278.