Some differences in the exponential tail behaviour of the fundamental absorption edge in amorphous and crystalline materials

Abstract

Some characteristics of optical absorption in the fundamental absorption tail are studied using the parameterΔ which describes the shape of the optical absorption edge of crystalline and amorphous materials. It follows from the experimental data thatΔ depends on the morphological state of material. Further, very pronounced linear temperature dependence ofΔ was found for crystalline materials whereas only a weak dependence was found for amorphous materials. A unique point of intersection has been observed for all theΔ=f(T) lines pertinent to various crystalline materials in unpolarized light.