Study of Zn1-xMgxSe and Zn1-xBexSe semiconducting crystals by Raman scattering

Wide gap II-VI mixed crystals containing Mg and Be are recently studied extensively for their application in constructing blue-green laser diodes. This work deals with experimental study of optical modes in Zn1-xMgxSe and Zn1-xBexSe semiconductors using Raman scattering method. Measurements have been performed at room and liquid nitrogen temperatures for Zn1-xMgxSe crystals with Mg content in the range 0 < x < 0,34 and for Zn1-xBexSe with Be content in the range 0 < x 0,26. From polarised Raman spectra the longitudinal (LO) and the transverse (TO) optical mode, corresponding to ZnSe- and MgSe - like modes in Zn1-x MgxSe and to ZnSe- and BeSe - like modes in Zn1-xBexSe, were determined. These lattice vibrations can be described by the modified random element isodisplacement (MREI) model.