AVS 49th International Symposium
    Organic Films and Devices Tuesday Sessions
       Session OF+SS+EL+SC-TuA

Paper OF+SS+EL+SC-TuA2
A New Crystalline Form of Pentacene: pi-stacked Thin Films Grown on Au(111)

Tuesday, November 5, 2002, 2:20 pm, Room C-102

Session: Organic Molecular Films
Presenter: J. Kang, University of Minnesota
Authors: J. Kang, University of Minnesota
X.-Y. Zhu, University of Minnesota
Correspondent: Click to Email
The recent demonstration of pentacene and related molecules in high-mobility field effect transistors (FETs), including superconducting FETs, has attracted great interest in this class of organic semiconductors. Carrier mobility is known to depend intimately on crystalline quality. In order to establish a molecular level understanding of structure-property relationship, we have carried out a scanning tunneling microscopy (STM) and spectroscopy (STS) study of the growth of crystalline pentacene thin films on Au (111). The use of high bias voltage (~ 5 V) and low tunneling current (~ 1pA) has enabled us to image, with molecular resolution, the growth of a new crystalline phase of pentacene well beyond the first a few layers. High resolution imaging shows that pentacene molecules form a pi-stacked crystalline phase with their long-axis parallel to the surface. This is attributed to the strong molecule-surface interaction, which seeds the growth of this new crystalline phase.