Chapter 8 - Properties of Thin Films

Abstract

The properties of thin films are primarily determined by the type of chemical element or compound they comprise and by the film thickness. Their optical, electro-optical, electrical, and mechanical behavior is also determined by structure, microstructure, surface and interface morphology, chemical composition, purity, and homogeneity. These are strongly influenced by the film preparation method, the chosen parameters, and postdeposition treatments. This chapter discusses properties and characteristics of films in the optical and electro-optical categories because these types constitute the most important applications of coatings on glass and plastics. The arrangement of atoms in a material is determined chiefly by the strength and directionality of the interatomic bonds. Typical for strong bonds, such as covalent, ionic, and metallic bonding, is a pronounced lowering of electron energies. Weak bonds are less easily defined, but can be viewed in terms of weak dipole attractions and quantum mechanically determined interatomic forces, the so-called van der Waals forces.