Inherent optical absorption in tellurium with uniaxial presssure

The paper deals with the experiment data on investigation of optical spectra of the edge absorption in single-crystal tellurium in the presence of the uniaxial pressure applied along C(P parallel C). The measurement are carried out at T=295 K and polarization normal to C-(E perpendicular C) axis. Within the interval of the used values of pressures P (up to 1000 kg/cm2) one reveals the transmission spectra shift to the short-wave side with the increase of the deformation value which is caused by the increase in the threshold energy Eg of interzone electron transitions. The pressure coefficient of the forbidden zone width (θEg/θP) perpendicular is estimated. The observable change of Eg is explained by the change in parameters of the trigonal tellurium lattice under the uniaxial deformation conditions. Based on the analysis of transmission spectra in the edge, a convenient procedure is suggested for estimating the forbidden zone width of a non-deformed crystal