In this work, tailor-made phosphonic acids are used as surface initiators for the growth of both dielectric and semiconductor polymers from barium titanate nanoparticles and transparent conductive electrodes respectively. For capacitor applications, grafting the polymer from the barium titanate surface gives a composite with high permittivity due to the inorganic inclusions as well as high breakdown strength, mechanical flexibility, and ease in processability due to the organic polymer. The polymer is grown using an atom transfer radical polymerization with catalyst in the ppm level and can be done with limited presence of air. The amount of polymer grown can be controlled in order to fabricate devices with varying polymer content to study its influence in device performance. Devices are created by simple blade casting without the need for any ball milling.

 

For transparent electrodes in solar cells, the growth of the donor phase directly from the substrate could lead to new morphologies, long term stability, and increased charge collection. We recently published a paper describing the growth of polymethylthiophene from ITO and some of its electrochemical properties.[1] Currently we are working on the optimization of the procedure to obtain smooth, thick polymer brushes that can be used to fabricate devices. Ongoing work involves X-ray photoelectron spectroscopy characterization of the starting monolayers and intermediate metallated species.

 

[1] Doubina, N.; Jenkins, J. L.; Paniagua, S. A.; Mazzio, K. A.; MacDonald, G. A.; Jen, A. K. Y.; Armstrong, N. R.; Marder, S. R.; Luscombe, C. K. Langmuir 2011, 28, 1900-1908.