Refractive Index in the Region of Excitonic Resonances in TlGaSe2 Crystals

Abstract

The low-temperature transmission and wavelength modulated transmission spectra of ТlGaSе2 crystals with a thickness of 7, 5.7, 4.7 μm were measured. Refractive index was calculated from interference observed in transmission spectra. The spectral dependences of the normal dispersion nа (Е║а) and nв (Е║в) and Δn = nа (Е║а) - nв (Е║в) on the long- wavelength and short-wave side of the ground states A, B and C of excitons are determined.