Role Of Electron-Phonon Interaction In The Temperature Dependence Of The Phonon Mode Frequency In Ii-Vi Compound Alloys

We present an experimental investigation of the temperature dependence of the TO-phonon mode frequencies for the HgTe-based II-VI semiconductor solid solutions. In the case of the ternary Hg-0.9 Zn0.1Te solid solution was shown a discontinuity in the temperature dependence of the HgTe-like TO- mode and of the ZnTe-like TO-mode, similar to the Hg0.885Cd0.115Te system [Sheregii et al., Phys. Rev. Lett. 102, 045504 (2009)]. A generalization of the theoretical temperature shift of the phonon mode frequency as analytic equation is derived that includes both the anharmonic contribution and the electron-phonon e-p interaction which in this case is returnable the electron subsystem effect on the phonon one. Data show that our equation satisfactorily describes the temperature shift of both Hg0.885Cd0.115Te and Hg-0.9 Zn0.1Te containing Dirac point (E-g = Gamma(6) - Gamma(8) = 0) although one of the two constants describing the anharmonic shift of the HgTe-like mode should be positive what is abnormal too. (C) 2016 WILEY-VCH Verlag GmbH & Co.