Critical point parameters deduced from the dielectric function in HgZnTe and CdZnTe alloys

Thickness measurement and optical properties of very thin ZnxCd(1 x)Te layers

“…This discrepancy could be due to uncertainties in the exciton binding energies associated to each CP. More important is that the bowing of the dependences in our paper is substantially larger than in [13]. This fact leads to a slight decrease of the CP transitions at low x values with respect to x = 0.…”

“…While E 0 dependence is very similar to that of [13], relatively large differences (some tenth of eV) are observed for E 1 and E 1 + 1 CPs. This discrepancy could be due to uncertainties in the exciton binding energies associated to each CP.…”

“…Figure 4(c) shows the variation of the energy E 0 with composition. For comparison, the dotted curve drawn in figure 4(c) gives E 0 variations at room temperature deduced from spectroscopic ellipsometry [13]. The agreement appears good for high x.…”

“…Thus, if all these parameters per CP of the two binary parents (ZnTe and CdTe) are known, one can calculate the spectral dependence of ε(ω) for the Zn x Cd 1−x Te alloys with arbitrary composition. Adachi et al have already analysed different alloys following this method [9][10][11], including Zn x Cd 1−x Te [9] also assuming the linearity between CP energies and x. Castaing et al deduced from the pseudodielectric function (measured by spectroscopic ellipsometry), the interband transition energies and their broadening parameters according to the CP model [13]. They showed that the bowing of the CP energies is small but not negligible.…”

Photoreflectance study in theE1andE1+Delta1transition regions of ZnTe

“…Since optical response is of great importance for many device applications, many efforts have been made to obtain optical response and, consequently, to determine the optical constants of ZnTe [1]. Recent spectroellipsometry (SE) studies on ZnTe have proven to be useful for determining the optical constants and deducing the critical-point (CP) parameters in this material [2][3][4][5][6].…”