Influence of the electron-phonon interaction on the temperature dependence of the phonon mode frequency in the II-VI compound solid solutions

Journal Article · Wed Jan 14 04:00:00 EST 2015 · Journal of Applied Physics

DOI:https://doi.org/10.1063/1.4905293· OSTI ID:22412849

Cebulski, J.; Sheregii, E. M. ^[1]; Marcelli, A.; Piccinini, M. ^[2]

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1. Centre for Microelectronics and Nanotechnology, University of Rzeszow, S. Pigonia 1, 35-959 Rzeszow (Poland)
2. INFN - LNF, Via E. Fermi, 44, I-00040 Frascati (RM) (Italy)

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{sub 0.9}Zn{sub 0.1}Te solid solution was shown a discontinuity in the temperature dependence of the HgTe-like T{sub 0}-mode and of the ZnTe-like T{sub 1}-mode, similar to the Hg{sub 0.85}Cd{sub 0.15}Te 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 Hg{sub 0.85}Cd{sub 0.15}Te and Hg{sub 0.90}Zn{sub 0.10}Te containing Dirac point (E{sub g} ≡ Γ{sub 6} – Γ{sub 8} = 0) although one of the two constants describing the anharmonic shift of the HgTe-like mode should be positive what is abnormal too. In the case of the Hg{sub 0.80}Cd{sub 0.20}Te and Hg{sub 0.763}Zn{sub 0.237}Te solid solution, the role of the returnable e-p contribution is negligible but a positive temperature shift for the HgTe-like modes occurs. This result does not allow to explain the positive temperature shift of these modes merely by the contribution of the (e-p) interaction. Indeed, the relativistic contribution to the chemical bonds induces an abnormal temperature shift of the electron states in Hg-based semiconductors—the effect is expected since the Hg d spin-orbit split contribution to chemical bonds may lead to an abnormal temperature shift of the HgTe-like modes.

• OSTI ID: 22412849
• Journal Information: Journal of Applied Physics, Journal Name: Journal of Applied Physics Journal Issue: 2 Vol. 117; ISSN JAPIAU; ISSN 0021-8979
• Country of Publication: United States
• Language: English

Related Subjects

75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
CADMIUM TELLURIDES
CHEMICAL BONDS
ELECTRON-PHONON COUPLING
ELECTRONS
L-S COUPLING
MERCURY TELLURIDES
PHONONS
SEMICONDUCTOR MATERIALS
SOLID SOLUTIONS
TEMPERATURE DEPENDENCE
ZINC TELLURIDES