Degradation of organic semiconductors in the presence of oxygen is one of the bottlenecks preventing their wide-spread use in optoelectronic devices. The first step towards such degradation in functionalized pentacene (Pn) derivatives is formation of endoperoxide (EPO), which can either revert back to the parent molecule or proceed to molecule decomposition. We present the study of reversibility of EPO formation through probing the photophysical properties of functionalized fluorinated pentacene (Pn-R-F8) derivatives. Experiments are done in solutions and in films both at the single molecule level and in the bulk. In solutions, degradation of optical absorption and its partial recovery after thermolysis were quantified for various derivatives depending on the solvent. At the single molecule level, low concentrations of each type of molecules were imaged in a variety of polymer matrices at 633 nm excitation at room temperature in air using wide-field fluorescence microscopy. Fluorescence time trajectories were collected and statistically analyzed to quantify blinking due to reversible EPO formation depending on the host matrix. To understand the physical changes of the molecular system, a Monte Carlo method was used to create a multi-level simulation, which enabled us to relate the change in the molecular transition rates to the experimentally measured parameters. At the bulk level, photoluminescence decay due to photobleaching and recovery due to EPO reconversion were measured for the same derivatives incorporated into various matrices. These studies provide insight into the synergistic effect of the local nanoenvironment and molecular side groups on the oxygen-related degradation and subsequent recovery which is important for development of organic electronic devices.
|Title of host publication
|Organic Photonic Materials and Devices XX
|Christopher E. Tabor, Francois Kajzar, Toshikuni Kaino, Yasuhiro Koike
|Published - 2018
|Organic Photonic Materials and Devices XX 2018 - San Francisco, United States
Duration: Jan 31 2018 → Feb 1 2018
|Proceedings of SPIE - The International Society for Optical Engineering
|Organic Photonic Materials and Devices XX 2018
|1/31/18 → 2/1/18
Bibliographical noteFunding Information:
We thank Dr. R. Grollman and K. Bilty for their contributions to the initial stages of this work. The National Science Foundation (DMR-1207309) and Oregon State University (OSU) URISC program (M. Li) are acknowledged for financial support. N. Q. thanks the OSU Graduate School for the Graduate Travel Award to present this work.
Copyright © 2018 SPIE.
- Monte Carlo
- Organic semiconductors
- single molecule uorescence spectroscopy
- uorescence intermittency
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Condensed Matter Physics
- Computer Science Applications
- Applied Mathematics
- Electrical and Electronic Engineering