EVOLUTION OF THE OPTICAL PROPERTIES OF CONJUGATED POLYMERS FOLLOWING METAL DEPOSITION. E. Ettedgui, G.T. Davis, Building 224, Room B318, Polymers Division, NIST, Gaithersburg, MD 20899; B. Hu, F.E. Karasz, Polymer Science and Engineering Department, University of Massachusetts, Amherst, MA, 01003 (301-975-4342; email:emile@enh.nist.gov)


Studies of the interface formation between metals and conjugated polymers provide valuable insight into the electronic properties of polymer based light emitting devices (PLED). Photoluminescence (PL) using 350 nm excitation and the visible absorption spectrum of a conjugated-nonconjugated block copolymer were monitored following the deposition of Au and Al. The deposition of 20 Å Au on POPV3P reduced the PL intensity by 40% and a broad absorption feature centered near 630 nm arose. The PL and absorption spectrum of the polymer recovered after the removal of Au. Al deposition, on the other hand, did not significantly affect the PL intensity or the absorption spectrum. Previous near-edge X-ray absorption fine structure studies have revealed that Au deposition results in the formation of interfacial states not present in the bulk polymer, while Al deposition does not. These new states likely form non-radiative sites which quench PL in POPV3P.