• Torres, J.
• Giraldo, J. J.
• Campos, A. M.

Abstract

<jats:p> The spectral variation of the effective dielectric constant in porous silicon thin films is modeled using effective medium theories. The pores in the material are supposed to be spheroid prolate inclusions in a homogeneous matrix. We employ modified Maxwell–Garnett and Bruggeman expressions obtained from previous work. Fitting to experimental reflectance spectra and the refractive index at the visible spectral range is satisfactory. Best results in both models are obtained using the spheroidal inclusions of 0.9 eccentricity. The best adjusted porosity values for two samples with different parameters of preparation are 47% with Bruggeman's expression and 67% with Maxwell–Garnett's expression, which are very close to the experimental ones of 44% and 67% respectively, obtained through gravimetric methods. Our model is useful for determining and for checking the influence of the preparation parameters on the optical and structural properties. </jats:p>

Topics

• porous
• impedance spectroscopy
• pore
• inclusion
• thin film
• dielectric constant
• Silicon
• porosity