Discipline: Nanoscience
Subcategory: Materials Science
Harold O. Lee III - Norfolk State University
Co-Author(s): Sam-Shajing Sun, Norfolk State University, Norfolk,VA
Organic and polymeric materials have gained widespread interest for potential future electronic and optoelectronic materials due to their intrinsic features such as lightweight, flexible, low-cost, easily possible, easily scalable, etc. Similar to their inorganic counterparts, the addition of other molecules, i.e. chemical doping, can change or enhance the optoelectronic properties of the host material allowing for tunability based upon the application that is desired. In this study, we doped P3HT:PCBM blends with various iodine concentrations and observed various changes in the electronic and/or optoelectronic properties of the blend system. Our studies revealed some important information and reasons why a 5% mole ratio doping would result in optimum electronic and optoelectronic performance.
Specifically, iodine solution doping was carried out by mole ratios of 1, 5, and 10% with respect to P3HT. Thin films were prepared by spin coating previously prepared solutions onto plain glass slides. It is important to note that films were dried individually, not all together, to prevent any cross contamination between doped samples. Dynamic Light Scattering, UV/Vis spectroscopy, photoluminescence spectroscopy, atomic force microscopy, and X-ray diffraction was conducted to study optoelectronic and morphological properties of these doped systems.
In summary, iodine doping of P3HT:PCBM composites induced significant changes in the electronic and optoelectronic properties of the materials. In solution, P3HT aggregation was characterized via UV/Vis spectroscopy, photoluminescence, and dynamic light scattering. In the solid state, the iodine doping induced surface smoothness and crystallinity in P3HT:PCBM thin films were characterized by UV/Vis spectroscopy, photoluminescence, atomic force microscopy, and X-ray diffraction. The mechanisms of iodine doping of P3HT:PCBM were better understood.
Funder Acknowledgement(s): National Science Foundation-CREST (NSF Award # HRD-1547771) and Department of Defense (Award #W911NF-15-1-0422).
Faculty Advisor: Sam-Shajing Sun, ssun@nsu.edu
Role: Primary author conducted all of the research.