| AVS 57th International Symposium & Exhibition | |
| Energy Frontiers Topical Conference | Wednesday Sessions |
| Session EN+NS-WeA |
| Session: | Nanostructures for Energy Conversion & Storage I |
| Presenter: | B. Rajesh, University of Houston |
| Authors: | B. Rajesh, University of Houston N. Badi, University of Houston and Integrated Micro Sensors, Inc. A. Bensaoula, University of Houston R. Supparesk, University of Houston T.R. Lee, University of Houston |
| Correspondent: | Click to Email |
Extensive interest is being invested into the research of nanodielectrics because of their promising applications in energy storage solutions as both discrete and embedded capacitors. They are useful in integral passive technology for miniaturization, improvement of power distribution and as decoupling capacitors. Their applications include, but are not limited to, high speed computing boards (servers, routers, super computers) and module boards (cell phones, PDA, note book computers). We fabricated high capacitance density dielectrics for flexible electronics by embedding core-shell type gold-silica nanoparticles in a polymer matrix using a coupled sol-gel procedure with laser engineering technique.
We report on fabrication of nanodielectric capacitors based on core-shell nanoparticles embedded in polyvinyl pyrrolidone (PVP) dielectric matrix. We developed a process chain to optimize the use of PVP as dielectric and measured its dielectric constant (K) as 7 at 10 KHz and breakdown field as 130V/μm. Monodispersed core-shell nanoparticles (NPs) are prepared with two different structures: 1) 35nm gold core – 95nm silica shell and 2) coating 35nm gold NPs with polymer compatible self assembled monolayer (SAM). Pre-processing is performed to uniformly disperse the NPs in a polymer matrix and to selectively form the polymer shell around each of the nanoparticles. Post-processing is carried out to spin coat on substrates and to cure under UV light to make capacitor slabs.
The results from SEM and AFM analysis, thermal and frequency response, breakdown dielectric strength and dielectric loss of the films for different loadings of NPs will be reported in the talk. K value of 20 and breakdown field of 50V/μm were measured for a dielectric with 10% loading of Au/SiO2 NPs. Resulting capacitance value of 11.5nF/In2 is in par with commercially available capacitor devices. It is worth mentioning that currently manufacturers use ceramic based dielectric material which makes it hard to manufacture (reproducibility, stability and cost) and shows limited flexibility (a requirement in modern printed circuit board technologies) due to high ceramic loading. Our fabricated nanodielectrics have the advantage of ease of fabrication and high flexibility due to the low metal loading.
It is forecasted that the effective permittivity of the dielectric and thereby the K value increases with loading of NPs till a percolation threshold is reached and then rapidly decreases with further loading. Future research is aimed at using other inexpensive metal NPs like silver and testing different polymers for best desirable characteristics of the capacitors.