THE TEMPERATURE-DEPENDENCE OF THE ENERGY-GAP IN CD0.22HG0.78TE .2. HALL-EFFECT MEASUREMENTS

Hall effect data evaluated with various assumptions regarding the ener gy band parameters are compared with the results of optical measuremen ts. The energy gap E(g) of an ideal crystal described by the Kane band model should be distinguished from the energy difference E(T) between conduction and valence band tail states which contribute also to the carrier transport. The temperature coefficient of E(g)(T) is proposed to be higher than that used in the well-known Hansen-Schmit-Casselman relation, while E(T) versus temperature varies more slowly as a conseq uence of a broadening of the band tails with increasing temperature.