Cc. Wu et al., TEMPERATURE-DEPENDENCE OF LATTICE VIBRATION-SPECTRA FOR HG1-XZNXTE ALLOYS, Semiconductor science and technology, 10(4), 1995, pp. 437-442
The far-infrared reflection spectra of Hg1-xZnxTe crystals with variou
s composition x have been measured at temperatures ranging from 90 to
295 K in the wavenumber region of 60 to 450 cm(-1). In all but the pur
e compounds, HgTe and ZnTe, a two To phonon structure is clearly obser
ved. The optical phonon frequencies are well determined by Kramers-Kro
nig integrations and dynamic dielectric function fitting. As the tempe
rature is increased, the lattice vibration frequencies of the ZnTe-lik
e optical mode decreases in the composition range x less than or equal
to 0.388. A similar situation is found between the temperature depend
ence of the frequencies of the HgTe-like To lattice vibration mode and
the temperature dependence of energy gap. This indicates that there i
s a correlation between the HgTe lattice vibration mode and the electr
onic structure of Hg1-xZnxTe alloys. The approaches which concern the
temperature dependence of electronic states and lattice vibration in s
emiconductors are discussed.