Determination of optical constants of real thin films

Abstract

A method is presented for determining the optical constants of films with a slightly rough upper surface and somewhat inhomogeneous over their thickness from normal incidence reflection and transmission measurements. It is shown how the film thickness and RMS height of surface irregularities can be calculated on the basis of measured absolute transmittances in the region of interference fringes.

Structural, optical and electrical properties of undoped polycrystalline hematite thin films produced using filtered arc deposition

“…A. Woollam Co. Inc.) to determine the refractive index n, extinction coefficient κ and film thickness. Additionally, the optical constants were calculated explicitly using the formulation of Szczyrbowski [33]. This approach considers a slightly rough film on a transparent substrate polished on both sides with known optical constants and includes the effects of thinfilm interference and multiple reflections.…”

Optical characterization and bandgap engineering of flat and wrinkle-textured FA0.83Cs0.17Pb(I1–xBrx)3 perovskite thin films

“…(7), where A is the imaged area. 16 The main advantage of averaging over height frequency is increased calculation speed, as the integrals in Eqs. (5) and (6) are one-dimensional and require far fewer computations of T (d + t) and S n (d + t) for the same level of precision.…”

“…13,16 The refractive index for the fused quartz substrate is modeled with a Sellmeier series, previously fitted to measurements of the substrate only. The effect of internal reflections in the substrate is also considered.…”

Importance of the band gap energy and flat band potential for application of modified TiO2 photoanodes in water photolysis

“…4a. The oscillations clearly seen in T(λ) and R(λ) result from the interference of light at both air-film and film-substrate interfaces and allow to calculate the absorption coefficient α by means of the envelope method [16]. The region over which the drastic drop of the transmittance coefficient occurs (3.25 eV < hν < 4 eV) corresponds to the fundamental absorption edge related to the forbidden band gap.…”