Chapter 4 Optical and photoelectrical properties of chalcogenide glasses

Abstract

This chapter discusses the optical and photoelectrical properties of chalcogenide glasses. To understand the nature of electronic processes in non-crystalline semiconductors, it is necessary to investigate their energy spectrum, the phenomena of charge carrier transfer, and the process of radiation interaction with such materials. The energy spectrum of electron states in the range hν > E g can be studied from the reflectivity spectrum of light in the fundamental absorption band where hν is the energy of quantum and E g the optical gap. Of special interest is the study of the optical features of noncrystalline semiconductors near the absorption edge. It is known that the absorption edge of noncrystalline materials is sensitive to the composition and the material structure as well as to external factors such as electric and magnetic fields, and optical, heat, electronic and other radiations. Under the influence of these factors, optical parameters of noncrystalline semiconductors suffer reversible and irreversible changes. The study of such phenomena not only clarifies the mechanisms of light absorption in the matter at significant disorder of its structure, but also suggests all possible practical applications, which are not always peculiar to crystalline semiconductors.