Optical study of ZnSexTe1−x alloys using spectroscopic ellipsometry

Abstract

We report pseudodielectric function data 〈ε〉=〈ε1〉+i〈ε2〉 of ZnSexTe1−x samples grown on GaAs substrates. The data were obtained from 1.5 to 6.5 eV using spectroscopic ellipsometry. Critical-point parameters were obtained by fitting model line shapes to numerically calculated second-energy derivatives of 〈ε〉. The bowing parameters of E0, E1, and E1+Δ1 were determined and were comparable to that of E0 quoted from the literature. We observed a monotonic increase of the linewidth of the E1 gap up to x=0.85, whereas that of E1+Δ1 showed a maximum value near x=0.5. We attribute this anomalous broadening of the E1 gap to sample microstructures developed in the low-Te composition alloys.

Optical properties of CdSexTe1−x epitaxial films studied by spectroscopic ellipsometry

“…Using this fact, we analyzed the Ψ and ∆ spectra for all of the samples and estimated the fundamental energy gap from these spectra. 9 In Fig. 2, we show these results along with a linear fit to the data points.…”

Spectroscopic ellipsometric analysis of ZnSe1−xOx layers with different O compositions

“…The solid and dotted lines represent the best fits with the experiment data. 34 The bowing parameters of ZnSe 1−x O x are 0.0014 for E 0 , 0.022 for E 0 + ⌬ 0 , and 0.007 for E 1 . The E 0 and E 0 + ⌬ 0 interband resonance can be clearly observed below and above 3 eV in Fig.…”