The research program carried out within the Institute for Polymers and Organic Solids continues to focus on developing a new class of chemically synthesized polymers --- conjugated polymers as materials for electronics and photonics ---and to focus on their special physical properties. Conjugated polymers are a unique class of materials: materials with the electronic and optical properties of metals and semiconductors in combination with the processing advantages and mechanical properties of polymers. The IPOS research program involves studies of semiconducting and metallic materials and the unique phenomena associated with their anisotropic, quasi-one-dimensional structures. Recent progress on semiconducting polymers as light emitting materials is particularly promising. As semiconductors with high quantum efficiency for photoluminescence, polymer emissive displays and polymer-based lasers.
The Institute is interdisciplinary involving the back and forth interplay between chemical synthesis, broadly based experimental physics, polymer processing and theoretical physics. The approach is to synthesize and study condensed matter materials directed toward desired physical properties, e.g., metals, semiconductors, nonlinear optical materials, laser materials, etc. We utilize the specificity of synthetic chemistry to create novel materials having desired structural features with the eventual goal of using these materials in technology. Experience has demonstrated that fundamentally new concepts and new phenomena continue to be uncovered through such studies of new materials.
Specific examples of recent accomplishments of special importance include the following:
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Placed the transport properties of "metallic" polymers on a firm scientific basis; quantitative demonstration of the disorder induced metal-to-insulator transition and identification of the critical regime.·
Discovery of ultrafast photoinduced electron transfer in conducting polymers mixed with controlled amounts of acceptors; the huge asymmetry in the forward and back charge transfer rates is analogous to "artificial photosynthesis". This remarkable phenomenon has opened the way to a variety of applications including high sensitivity plastic photodiodes, efficient plastic solar cells and, more recently, high sensitivity biosensors.·
Leading role in the development of the science and technology of high efficiency light emission from polymer light-emitting diodes and polymer light-emitting electrochemical cells.·
Discovery of semiconducting polymers as materials for solid state lasers.The Institute is currently involved in a transition. After more than fifteen years as Director, Professor Heeger will step down during the 1999-2000 academic year. Professor G. Bazan will take on the responsibilities of Director. Prof. Bazan arrived at UCSB in the summer of 1998; he has an active research program underway focused on the synthesis of conjugated polymer and oligomers. Bazan and Heeger will continue to function as a key members of IPOS. Bazan and Heeger have recently initiated a new program directed toward using semiconducting polymers in biosensor applications. This new IPOS initiative will be carried out through a multi-investigator collaboration involving (in addition to Bazan and Heeger and their students and post-doctoral researchers):
Dr. Duncan McBranch (Physics/Biophysics) Los Alamos National Lab
Dr. David Whitten (Chemistry/Photochemistry) Los Alamos National Lab
Peter S. Heeger (MD & Immunology) Case Western Reserve Univ.
Professor Fred Wudl (Chemistry) UCLA
This strong collaboration exists, initial funding has been successfully generated, and work in this area is underway. Other principal contributors to the IPOS research program are Dr. Daniel Moses and Dr. Vojislav Srdanov.
