Technical: The scientific goal of this CAREER award is to advance the fundamental understanding of organic semiconductors through four interrelated materials science research tasks. The first task focuses on the role of the growth process and grain size distribution, which play a crucial role for the electronic and optical properties of organic materials. The morphology is quantified using methodologies adapted from inorganic thin film studies. The second task is based on a reduction in dimensionality through the fabrication of organic superlattices (coherent multilayers), in which interface properties dominate. Similar structures for metals resulted in the discovery of giant magneto-resistance and the data storage revolution. The PI plans to combine impedance spectroscopy and temperature-dependent measurements to gain insight into the charge transport mechanism of organic superlattices. In collaboration with chemists, the PI will engineer nano-building blocks with ferromagnetic properties that can be tuned as needed. A concept of magnetically tailored one-dimensional ferromagnetic chains is thereby introduced. The fourth task addresses the issue of energy conversion efficiency in organic solar cells. Recently, blends of n- and p-type semiconductors were discovered to significantly increase the performance of organic photovoltaic cells. In a new concept, the PI seeks to build nano-columns based on porous alumina templates that are expected to boost the efficiency and grant additional structural control and potential for optimized design.
The project addresses basic research issues in a topical area of materials science with high technological relevance. Organic semiconductors are valuable for various electronic and photonic applications and potentially large societal impacts. The PI plans to establish a research and teaching laboratory at the California State University, Long Beach, which serves the urban, ethnically and culturally diverse student community. This CAREER award has multiple faceted education impacts. The inclusion of organic semiconductors in the curriculum provides unique and necessary training to students entering a rapidly expanding market for organic semiconductors. Addition of demonstrations to the K-12 Science Learning Center helps convey the relevance of nanotechnology and organic semiconductors.
