The materials are insulators; thus, no flow of the electric charges can be performed through the material. The dielectric materials are not loosely bound or free, causing dielectric polarization that offers positive charges in the field's direction and negative charges that shift opposite the electric field. The material performance determines by a dielectric constant (k) that defines the material's storage capacity for the electrical charge. Materials with high-k values can be used as gate dielectrics in metal-oxide-silicon (MOS) transistors, memory cells, and supercapacitors. On the other hand, materials with low-k values are essential as electrical insulators.