1. Charge Transfer and Charge Transport in Nanofibers of
Conjugated Polymer and ZnO Nanoparticles
Zhengtao Zhu, Department of Chemistry, South Dakota School of Mines and Technology
Hybrid organic semiconductor/inorganic nanomaterials are of great interest not only as potential materials for applications in high efficient energy conversion but also as model systems for studies of the fundamental physical properties and interactions at the nanometer scale. In recent years, progresses have been made in understanding the mechanism of photoinduced charge transfer process and the effect of the morphology and the structures of the inorganic nanomaterials on the charge transfer properties. However, the effects of polymer chain conformation and order/disorder in the nanocomposites on the exciton formation and dissociation, charge transfer, and charge transport properties have not been well addressed. Our work aims at investigating the optical and charge transport properties of nanocomposite of conjugated polymer and ZnO nanoparticles prepared through electrospinning process in order to elucidate the effects of morphology, polymer chain conformation, and confinement on the physical properties of the electrospun nanocomposite materials.
We have successfully studied the fluorescence emission spectra of electronspun MEH-PPV/PEO nanofibers with differing MEH-PPV/PEO compositions. A typical fluorescence microscope image and fluorescence spectrum of these nanofibers is on the right.
The notable outcomes of the these studies include:
Successfully preparation of MEH-PPV nanofibers by electrospinning process.
Evidence of less aggregation of the MEH-PPV polymer chains in electrospun fibers.
No polarization dependence of fluorescence in a single nanofiber observed with confocal fluorescence microscope.
Our next goal will be to incorporate ZnO nanoparticles in the electrospun conjugated polymer nanofiber and to study the charge transfer process in the composite fibers.
Typical MEH-PPV nanofibers
(Fluorescence image)