Pressure Dependence of Reflectivity of Se: Experimental Evidence for Large Local-Field Corrections

Abstract

The pressure dependence of the reflectivity of trigonal and amorphous Se has been measured between 1.1 and 4.5 eV using a new technique. The results indicate that local-field corrections are large. Structure near 2 eV suggests a localized excitation in both the amorphous and the crystalline material.