Description of vibrational properties of random alloy ZnTe_1–xSe_x within the percolation model

Abstract

We discuss the classification of the phonon type behavior of semiconductor alloys as apparent in the Raman and infrared spectra, i.e. in terms of types (i) 1‐bond→1‐mode and (ii) 2‐bond→1‐mode (both covered by the Modified Random Element Isodisplacement model, operating at the macroscopic scale), and also (iii) the modified 2‐mode type (exceptional), in the framework of the recent 1‐bond→2‐mode percolation model based on a description of the alloy disorder at the mesoscopic scale. The leading systems of types (i) and (iii), i.e., InGaAs and InGaP, respectively, were earlier shown to obey the percolation model. The aim of this work is to investigate whether the percolation model further extends to the leading system of the last type (ii), i.e. ZnTeSe. With this end in view, we perform a careful re‐examination of the Raman and infrared spectra of this alloy, as available in the literature. Special attention is awarded to the discussion and modeling of the puzzling multi‐mode infrared reflectivity spectra. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)

Vibrational spectroscopy of compound semiconductor nanocrystals

“…Note that for Cd 1−x Hg x Te, as shown by a recent study [316], the low-temperature lattice dynamics is somewhat more complicated; the same applies for Cd 1−x Zn x Te, where a fine structure in the far-infrared spectrum was reported [317]. Besides Cd 1−x Zn x Se [299][300][301], the 'mixed' behaviour, when an additional, usually weak, band appears in the spectrum, was reported for the much less investigated ZnSe 1−x Te x [238,318], Cd 1−x Mn x S [311], Zn 1−x Mn x Te [315], Zn 1−x Mn x Se [319,320], and Zn 1−x Be x Se [292] solid solutions. A detailed analysis of theoretical approaches to the criteria for one-mode or two-mode behaviour of solid solution systems can be found in earlier studies, including reviews [21,286,289] and references therein.…”