In this award funded by the Experimental Physical Chemistry Program of the Division of Chemistry, Professor John B. Asbury of the Pennsylvania State University will use two-dimensional infrared spectroelectrochemistry to study the molecular structures of defects in organic electronic materials. When electrons or positively charged carriers (termed holes) become trapped at defects in organic electronic materials, the electrical functionality of the materials is significantly reduced. The research funded by this award will use the dynamics of molecular vibrations in conjunction with their frequencies to elucidate the structures of defects in organic photovoltaic materials. In particular, defects will be charged electrochemically allowing them to be examined with two-dimensional infrared spectroscopy. The vibrational dynamics and 2D line shapes of charged defects will be compared to the corresponding features of the neutral materials for which structural assignments are known, thus facilitating structural elucidation of the defects. This approach will be used to establish predictive relationships among the structural and electrical characteristics and the corresponding defect structures and energetic distributions in organic photovoltaic materials.
The development of two-dimensional infrared spectroscopy as an analytical tool to examine defects will impact the organic electronics field by developing predictive structure-property relationships. Knowledge of these relationships will guide the rational design of organic photovoltaic materials that resist the formation of or are tolerant to defects, leading to the development of inexpensive solid state solar cells with greater than 10% power conversion efficiency. The understanding of charged defects will also facilitate the development of inexpensive lighting and display technologies based on organic electronic materials. The interdisciplinary nature of the research program will stimulate graduate and undergraduate researchers to work at the interface of ultrafast spectroscopy and materials disciplines. The educational plan is firmly rooted in the recommendations of the National Academies for enhancing the science and technology enterprise in the United States. Special emphasis is placed on targeting secondary school science education by involving in-service high school teachers in the research program supported by this award and by developing summer curricula for students from under-performing high schools through the Upward Bound Math and Science program of the U.S. Department of Education.
