Polymer-Nanocrystal Nanocomposites: Device Concepts in Capacitors and Multiferroics

Nanotechnology offers a variety of pathways to novel and low cost device fabrication for a future that will undoubtedly contain literally billions of ubiquitous electronic devices. Nanocomposite metal−insulator−metal (MIM) capacitors are of interest due to the possibility of reducing the number of discrete components in printed circuit boards, and alternatively using embedded or directly printed capacitors for nanopackaging in conjunction with integrated circuits. Flexible substrates also become candidates when employing low processing temperatures. In addition to compatibility with nanomanufacturing, the prospect of designing a nanocomposite dielectric, by combining colloidal nanoparticle fillers and polymer hosts, lends itself very well to the idea of tunability of the mechanical and electrical properties. In exploring combinations of complex oxide materials and polymers, the field goes beyond simple capacitors, towards multiferroic devices in which the potential overlap of magnetic permeability with permittivity can produce enactable devices for magnetodielectrics and magnetoelectrics. Our work in solution processing of inorganic oxide dielectrics and multiferroics, using a modified sol-gel approach allows for the preparation of a variety of formulations that can be treated as inks for deposition as layers and/or for the design of novel nanocomposite films. Starting with high dielectric materials, we discuss nanocomposite capacitance based energy storage, and progress to materials development for multiferroic nanocomposites.