Oxidation characteristics of single molecule MEH-PPV with a high energy hole transport layer

PHYS 502

Joshua C. Bolinger, jcb2873@mail.utexas.edu1, Kwang Jik Lee2, and Paul F. Barbara, p.barbara@mail.utexas.edu1. (1) Department of Chemistry and Biochemistry and the Center for Nano- and Molecular Science and Technology, University of Texas at Austin, 1 University Station #A5300, Austin, TX 78712, (2) Department of Chemistry, University of Texas, Austin, TX
Oxidation characteristics of single molecule poly[2-methoxy-5-(2'-ethylhexyloxy)-p-phenylene vinylene] (MEH-PPV) was investigated using the novel technique of Fluorescence-Voltage single molecule spectroscopy (FV-SMS). Fluorescence quenching at low forward bias (~2.5 V) due to the efficient hole injection was observed in the MEH-PPV single molecule devices where thin film (~25 nm) of the CBP layer was thermally deposited. However, the [poly (9,9 '-dioctylfluorene-co-benzothiadiazole)] (F8BT) single molecules devices showed fluorescence quenching at much higher bias (7 V), which is ascribed to the higher highest occupied molecular orbital (HOMO) level of F8BT. This is similar to what we already observed in the devices where poly(3,4-ethylenedioxythiophene) poly(styrenesulfonate) (PEDOT:PSS) was used as the hole injecting/transport layer. We expect this new set of the device system combined with the FV-SMS technique can unravel some complicated properties of the organic devices such as deep trapped holes by reducing/removing the electric field effect and other heterogeneities.
 

PHYS Poster Session - Nanostructured Materials and Nanophotonics
7:30 PM-10:00 PM, Wednesday, April 9, 2008 Morial Convention Center -- Hall A, Poster

Division of Physical Chemistry

The 235th ACS National Meeting, New Orleans, LA, April 6-10, 2008