Pentacene Grown on Self-Assembled Monolayer: Adsorption Energy, Interface Dipole, and Electronic Properties
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- 作者：Aloke Kanjilal ; Luca Ottaviano ; Valeria Di Castro ; Marco Beccari ; Maria Grazia Betti ; Carlo Mariani
- 刊名：Journal of Physical Chemistry C
- 出版年：2007
- 出版时间：January 11, 2007
- 年：2007
- 卷：111
- 期：1
- 页码：286 - 293
- 全文大小：481K
- 年卷期：v.111,no.1(January 11, 2007)
- ISSN：1932-7455
文摘
The energetic, the morphology, the interface dipole formation, and the electronic states of pentacene grownon a self-assembled monolayer (SAM) of benzenethiolate on the Cu(100) surface are investigated bycomplementary structural and spectroscopic techniques. The growth morphology of the heterostructure hasbeen investigated by atomic force microscopy (AFM), low-energy electron diffraction (LEED), Auger electronspectroscopy (AES), and photoemission spectroscopy, inferring tightly packed arrangement of grains constitutedof pentacene molecules with nearly perpendicular orientation, when a single-layer is deposited on top of thebenzenethiolate-SAM. The adsorption energy of the pentacene single layer on the benzenethiolate bufferlayer (Ea = 1.16 eV 
112 kJ/mol) is found much weaker than for pentacene on the copper surface, asestimated by thermal desorption spectroscopy (TDS). The evolution of the spectral density of electronic statesin the valence band, obtained by high-resolution ultraviolet photoelectron spectroscopy (HR-UPS), confirmsthe weak interaction of the pentacene molecules with the benzenethiolate-SAM and the formation of asemiconducting heterostructure, with a hole injection barrier reduced to 0.95 eV with respect to the pentacene/Cu interface.
112 kJ/mol) is found much weaker than for pentacene on the copper surface, asestimated by thermal desorption spectroscopy (TDS). The evolution of the spectral density of electronic statesin the valence band, obtained by high-resolution ultraviolet photoelectron spectroscopy (HR-UPS), confirmsthe weak interaction of the pentacene molecules with the benzenethiolate-SAM and the formation of asemiconducting heterostructure, with a hole injection barrier reduced to 0.95 eV with respect to the pentacene/Cu interface.