THE TEMPERATURE-DEPENDENCE OF THE ENERGY-GAP IN CD0.22HG0.78TE .1. OPTICAL MEASUREMENTS

The energy gap E(g) is accurately determined from interband Landau lev el transitions observed in spectral measurements of photoconductivity at low temperatures in an external magnetic field. The temperature dep endence of the optical absorption coefficient is measured on samples w ith different slopes of the exponential Urbach absorption edge. The re sults are compared with empirical formulae reported for E(g)(x, T). In the temperature region 10 to 300 K, the best agreement is found for t he relation published by Seiler et al., but with a modified value of t he temperature coefficient.