Refractive-index behavior of ternary chalcopyrite semiconductors

Abstract

Refractive-index dispersion data for 11 I-III-VI2 and II-IV-V2 chalcopyrite semiconductors are analyzed with a view towards obtaining a good representation of the data, values of physically meaningful parameters, and estimates of errors. Using a moment decomposition analysis, it is found that (i) only four parameters (three electronic and one lattice) are required to fit each dispersion curve, (ii) all differences between chalocopyrites and their zinc-blende binary analogs can be viewed as simple band-gap-shift effects, (iii) in contrast to cuprous halides, oscillator strength contributions from d-electron valence states in Cu and Ag chalcopyrites appear to be negligible, (iv) energy downshifts in chalcopyrites involve the entire ε2 spectrum, and (v) there is no clear quantitative correlation between structural distortions in chalcopyrites and anisotropies in optical parameters related to the birefringence. Finally, a brief discussion of the applicability of model ε2 spectra to descriptions of refractive-index dispersion and related optical effects is presented.

Optical absorption and dispersion characterizations of CuGaSe2 thin films prepared by flash evaporation technique

“…As observed, E 0 ≈ 2 E g in agreement with the relation stated in the literature [38]. On the other hand, an important achievement of WD model is that related to the dispersion energy, E d , to other physical parameters of material through the following empirical relationship [39,40]:…”

“…For the sample under investigation, Z a = 2, N e = 8, and N c = 4 [39] this yields to β = 0.39 eV which shows covalent crystal. This results is in agreement with that published by Wemple et al [39] The dielectric constant is partially due to free electron and partially due to bound electrons as represented by the following relation [40]:…”

Preparation and Study of Structural and Optical Properties of Chemical Bath Deposited Copper Indium Diselenide Thin Films

“…The evaluated refractive index values are in the range 2.40-3.18 (Fig. 7) and are in agreement with earlier reports [45,46]. As the wavelength increases the refractive index decreases in the lower wavelength region and becomes constant in the higher wavelength region.…”

The influence of the substitution of Se for Sn on the thermal, optical and dispersion properties of Ge14Se86−xSnx thin films

“…The parameter E 0 is found, in our case, to be E2E g which is in good agreement with that mentioned by Tanaka [32]. The dispersion energy E d is known to be related to other physical parameters of the material through the empirical relationship [53]:…”