Photoelectron Spectroscopy Studies of Structure-Property Relationships in Perfluoroalkylfullerene-Based Electron- Acceptor Materials for Organic Photovoltaic Active Layers
EMSL Project ID
42332
Abstract
This project will focus on understanding of the fundamental relationships between molecular structures of perfluoroalkylated fullerenes (PFAFs) and their electronic properties in the gas-phase, in solution and in thin films. PFAFs are new-generation electron acceptors for thin-film organic photovoltaics (OPV) which electron accepting ability can be tuned in the unprecedented wide range. They possess exceptional thermal stability, high solubility and may form long-lived radical anions in solution. For the successful design of the active layers for OPVs, one needs to understand (1) how molecular structures of PFAFs are related to their electronic properties,(2) the role of solvation processes and their effect on redox properties in solution, (3) what are the electronic properties of the thin films of PFAFs and how they are related to the electron affinities in the gas-phase, (4) how the electron affinity of the thin films change when acceptor is blended with the donor or when a bilayer films are formed. Currently such comprehensive set of data is not available for any kind of organic OPV acceptors, which leaves many of above questions unanswered. Due to their unique properties PFAFs are perfectly suitable molecular systems for which a complete set of data can be accurately measured and computationally modeled. In this project, we shall apply the unique expertise of the CSU team in the synthesis, isolation, structural and electrochemical characterization of the PFAFs with the expertise of Dr. X. B. Wang from Washington University & Pacific Northwest National Laboratory in the Low-Temperature Photoelectron spectroscopy of negative ions and in collaboration with the theorist Dr. Alexey A. Popov of Leibnitz Institute of Solid State and Materials Research in Dresden, Germany to advance fundamental understanding of the relationship between electronic properties of PFAFs in the solution and gas phase. We shall use EMSL electron spectroscopy facilities under leadership of Dr. Engelhard of EMSL to determine surface electron affinity of the thin films of PFAFs and donor-acceptor blends and bilayers, which will guide us in the controlled design of the new type of OPV devices.Project Details
Project type
Exploratory Research
Start Date
2010-11-01
End Date
2011-11-06
Status
Closed
Released Data Link
Team
Principal Investigator
Team Members
Related Publications
Kuvychko IV, JB Whitaker, BW Larson, T Folsom, N Shustova, S Avdoshenko, YS Chen, H Wen, XB Wang, L Dunsch, AA Popov, OV Boltalina, and SH Strauss. 2012. "Substituent Effects In a Series of 1,7-C60(RF)2 Compounds (RF = CF3, C2F5, n-C3F7, i-C3F7, n-C4F9, s-C4F9, n-C8F17): Electron Affinities, Reduction Potentials, and E(LUMO) Values Are Not Always Correlated." Chemical Science 3(5):1399-1407. doi:10.1039/C2SC01133F