Appearance of Absorption in the Visible Range in the Microwave-Induced Dielectric Gibbsite

摘要

Dielectric and semiconductive materials are widely used in different areas of solid-state electronics [1—4]. One of the most important characteristics of material is the band gap (E_g), which determines, among other properties, the optical characteristics of a material. The numerical value of the band gap makes it possible to classify a material with semiconductors or insulators. Materials with E_g >3 eV are attributed to dielectrics and those with E_g<3 eV, to semiconductors [2, 3]. The band gap is a fundamental parameter depending on the chemical bond nature and the structure of the condensed phase. As a rule, the band gap is defined as the gap between the top of the valence band and the bottom of the conduction band [5—7]. The notion of band gap is also extended to disordered and defect-rich phases, including amorphous phases [2, 6].