On the temperature dependence of the energy gap in PbSe and PbTe

Abstract

A detailed temperature dependence of the energy gap E0 in the PbSe and PbTe was obtained from the transmittance measurements. A non-linear change of E0 in the vicinity of the Debye temperature was noticed. An attempt to find an empirical formula describing the experimental dependence E0(T) led to the conclusion that the non-linear change can be attributed to the electron interaction with the optical phonons.