Room-Temperature Ferromagnetic Polymers with Nanoscale Phase Separation and Spin Transport in the Nanodomains
Magnetic field effects (MFE) in organic electronic materials and devices have recently caught the attention of the spintronics community. It is generally believed that organic semiconductor materials are nonmagnetic at room temperature (RT), but this has been found to not necessarily be true in certain polymers with internal charge transfer nanostructures. We recently discovered that polymer semiconductors, such as poly(3-hexylthiophene) (P3HT), can have room temperature (RT) ferromagnetic properties in their crystalline phase and when mixed with phenyl-C61-butyric acid methyl ester (PCBM) (see figure) with nanoscale phase separation. Tens to hundreds nm size domains are clearly observed by magnetic force microscopy (MFM), and the ferromagnet was confirmed by superconducting quantum interference devices (SQUID). The goal of this project is to investigate and understand the mechanism of the room-temperature (RT) ferromagnetic nanoscale semiconducting polymer and the correlated MFE. Three fundamental aspects of organic spintronics will be addressed:
- Study the origin of the room temperature ferromagnetic properties of the nanoscale-phase separated film.
- Investigate the spin transport behavior in ferromagnetic polymeric semiconductor nanodomains.
- Explore the enhanced device performance of polymer solar cells and new spintronic devices via controlled MFE.
The success of this project will lead to the theoretical base for a new family of RT organic magnetic materials and new applications in electronic devices for energy harvesting, information storage, and many others.