Optical properties of SbI3 single crystalline platelets

Optical parameters of platelets of crystalline antimony triiodide (SbI 3 ) have been evaluated using spectrogoniometric interference spectroscopy technique. Spectral characteristics of real parts of refractive indices of radiation with electric vector normal and parallel to the optical c -axis of SbI 3 crystalline platelets (i.e. n o , n e – refractive indices for ordinary and extraordinary rays) have been shown. The temperature dependences of spectra of optical parameters ( n o and absorption coefficient of radiation with electric vector normal to the optical c -axis) have been presented. The temperature dependences of fitted optical indirect allowed energy gap of SbI 3 , Urbach energy and phonons energies are the main findings of the presented work. The obtained results have been compared with literature data.