Reflectance spectra of crystals of the ZnTe-CsTe system

The reflection spectra of undoped ZnTe and CdTe crystals as well as ZnTe crystals doped with Cs and Ga2O3 and Znsub(x)Cdsub(1-x)Te solid solutions with x=0.2, 0.4, 0.5, 0.6, 0.7, 0.8 are investigated. The solid solution crystals and the ZnTe:Cs crystals were prepared with the isothermal method. All samples have p-type conduction. The hole concentration determined from Hall-effect measurements at 300 K ranged from 2.1016 m-3 for CdTe to 1019 m-3 for ZnTe and 2.1020 m-3 for ZnTe:Cs. The Ga2O3 doped ZnTe crystals were grown from a molten solution. The reflection spectra were measured by the standard methods at selected wavelengths at 300 K and 90 K in the range of 1-5.5 eV. The accuracy is 0.2-0.3%. Typical spectra are shown. The positions of reflection peaks in the ZnTe-CdTe system are given. In the spectra of all samples exciton peaks E0, and peaks E2 and E1+Δ1 are found, as well as the triplet peak A (A1, A2, A3) and the peaks E1, E1+Δ1, B1, B2, B3. Samples of a certain composition of the ZnTe-CdTe system exhibit a strong influence of the ''aging'' of freshly cleaved samples on the spectra: the reflection in the vacuum ultraviolet range fell gradually with time and the details of the complex structure became blurred. The obtained results are compared with data from other papers