Photoemission studies of lead sulfide-polymer nanocomposites

PHYS 505

Amanda T. Wroble, awrobl2@uic.edu, Daniel J. Asunskis, asunskis@uic.edu, Adam M. Zachary, azacha1@uic.edu, Igor L. Bolotin, bolotin@uic.edu, and Luke Hanley, lhanley@uic.edu. Department of Chemistry, University of Illinois at Chicago, MC 111, 845 W Taylor St, 4500 SES, Chicago, IL 60607
Lead sulfide nanocrystals (PbS NCs) have shown potential for use in optoelectronic applications due in part to their size-tunable band gap. PbS NCs are grown directly into a polymer matrix to control the size and surface chemistry of the resulting NCs. Transmission electron microscopy shows that PbS nanocomposites grown by either colloidal techniques or gaseous deposition using a cluster beam deposition source contain PbS NCs. Photoemission spectroscopy is used to study PbS nanocomposite films prepared by both methods. X-ray photoelectron spectroscopy (XPS) confirms that PbS is present and that there is no significant bonding between the PbS NCs and the polymer. Soft-XPS using photon energies of 200-300 eV available at a synchrotron radiation source provides surface sensitivity to observe the interaction of the PbS NC surface with the polymer matrix and is compared to results obtained using 1487 eV photon energy.