EE FY00 report: nanostructure multilayer materials for capacitors

Only two intrinsic approaches to increasing the density of energy stored in capacitors are known: (1) Increase the Dielectric Constant while maintaining the breakdown filed; and (2) Increase the breakdown field for a given dielectric constant material. The maximum energy density, E{sub 0} (Joules/cm{sup 3}) that can be stored in the dielectric of a capacitor is given by: E{sub 0} = 1/2 k {var_epsilon}{sub 0} V{sub b}{sup 2} (Joules/cm{sup 3} dielectric). Where k is the relative permittivity (dielectric constant), {var_epsilon}{sub 0} is the permittivity of free space (8.894 x 10{sup -14} F/cm) and V{sub b} the dielectric material breakdown field. In this project we have successfully developed capacitor structures using dielectric materials with 3 < k < 50 that exhibit high breakdown fields. The observed performance of these capacitors as characterized by the energy stored per unit volume of dielectric at V{sub b} are compared on the basis of the breakdown field in Figure 1.