Parametric modeling of the dielectric functions of InAsxP1 − x alloy films on InP

•We report an analytic expression of the dielectric functions of InAsxP1 − x films.•The dielectric function spectra are obtained by spectroscopic ellipsometry.•To obtain analytic expressions for these data, we use the parametric model.•Dielectric functions of arbitrary compositions can be calculated.

We report an analytic expression that accurately represents the dielectric functions ε = ε1 + iε2 from 1.5 to 6.0 eV of InAsxP1 − x alloy films over the entire composition range 0 ≤ x ≤ 1. We use the parametric model (PM), which describes the dielectric functions of semiconductor materials as a sum of Gaussian-broadened polynomials. The dielectric function spectra are those that we obtained previously by spectroscopic ellipsometry for the specific compositions x = 0.00, 0.13, 0.40, 0.60, 0.80, and 1.00. The PM reconstructions are in excellent agreement with the data. With the information provided here, dielectric functions of arbitrary compositions can be calculated.