Thin Films for High Energy Density Capacitors: A Materials Science Case Study on Zirconium and Tantalum Oxides and Their Polymer Laminate Composite Films

Pulsed power applications involve transformation of electrical energy into high-peak power pulses through capacitors. There is an immediate need for fast-response capacitors with decreased volume, weight, and cost for pulsed power applications and power distribution systems. This research challenge is dominated by energy density. Energy density is directly related to dielectric properties such as dielectric polarization, conductivity and breakdown strength of the capacitor dielectric. This work correlates processing and microstructure of single and multiple component dielectric films with their dielectric properties. The inorganic materials studied here include zirconium oxide and tantalum pentoxide reactive sputtered films. Oxide films were combined with different polymers (polyvinyldene flouride-triflouroethylene, polypropylene and polyethylene terephthalate) to produce two different kinds of laminate composites ? oxide on polymer and polymer on oxide. Permittivity and conductivity differences in the polymer and oxide films result in an impedance contrast which was modeled through Monte Carlo method in addition to the experimental characterization.