The temperature dependence (4.2 to 293 K) of the resonance energies of excitonic transitions in II–VI compounds

Abstract

Abstract Excitonic reflectivity spectra R( hw ) are measured by a digital technique for a number of II–VI compounds within a wide temperature range from 4.2 up to 293 K. The exact position of exciton resonance energy within the experimental R( hw ) profiles is determined by comparison with reflectivity curves calculated in the model of bulk excitonic oscillator with classical dispersion and exciton‐free surface layer. The temperature dependences of exciton resonance energies thus obtained are found to satisfy the known Varshni formula which includes two empirical parameters. These are determined for each compound under study, so that reference data become available for the position of exciton resonance at any temperature ranging from 4.2 up to 293 K.