High-Energy-Density Capacitors by Aerosol Combustion

Improved energy density capacitors are needed to reduce the size of spacecraft components. Current performance (-2 J/cm3) is limited by processing technology and not by inherent material properties. Spire proposes to use metalorganic chemical vapor deposition (MOCVD) with spray injection of reactants (aerosol combustion) to achieve high dielectric constant, high breakdown strength insulators capable of capacitively storing more than 400 J/cm3. Optimization of the position where reactants are volatilized (on the substrate surface, just off the surface, far from the surface) is necessary for rapid growth of a defect free film, the key to success in this program. Existing research with reactants in the vapor phase has demonstrated the material properties needed for capacitors with dimensions on the scale of integrated circuit devices (operation at under 10 volts and few square microns area). In Phase I, Spire will demonstrate that the technology can be extrapolated to larger devices, specifically fabricating a 1 kV, one microfarad capacitor with low dielectric loss and low leakage current. Specific NASA applications, aside from miniaturized power units, would include significant reduction in weight and volume for capacitors such as those used to power plasma thrusters.