From Growth to Electronic Structure of Dipolar Organic Semiconductors on Coinage Metal Surfaces

In this thesis, I present a comprehensive study of the interfacial electronic structure and thin film growth of two types of dipolar organic semiconductors on noble metals by employing a surface science approach, which underlines the critical role of surface electronic states in determining the interfacial electronic structure and self-assembly of organic semiconductors. I show that the electronic structure at organic/metal interfaces is complex and depends on important factors such as molecular adsorption configuration, surface/molecule coupling strength, reactivity of the substrate, molecular electrostatics, and local film structure. I demonstrate the fundamental capability of the image potential states and resonances in probing the local film environment, especially in systems consisting of inhomogeneous film structure. I also show that the presence of adsorbates on a surface allows one to investigate quantum mechanical interference effects otherwise not accessible on the bare surface. The dipolar organic semiconductors studied here are vanadyl naphthalocyanine (VONc) and chloroboron-subphthalocyanine (ClB-SubPc). The single crystals of gold and copper with hexagonal surface symmetry (111) were used to investigate the interfacial properties of VONc and ClB-SubPc, respectively. The fundamental understanding of self-assembly of large π-conjugated organic semiconductors on metals is a crucial step in controlling fabrication of supramolecular structures. Here, I provide a first step in this direction with a detailed and quantitative analysis of molecular nearest-neighbor distances that unravels the fundamental intermolecular interactions of organic semiconductors on transition metal surfaces. I additionally investigated the interfacial electronic structure of these organic semiconductors to examine the relation between molecular adsorption orientation and charge transfer across the interface.

Name thesis:degree_name

Ph.D.

Level thesis:degree_level

doctoral

Discipline thesis:degree_discipline

Graduate College

Grantor dc:publisher

The University of Arizona.

Year dc:date.issued

2014

Author dc:creator

• Ilyas, Nahid

Advisor dc:contributor.advisor

• Monti, Oliver L. A.

Committee members dc:contributor.committeemember

• Monti, Oliver L. A.
• Saavedra, S. Scott
• Pyun, Dong-Chul (Jeffrey)
• Huxter, Vanessa

• Intermolecular Interactions
• Organic Interfaces
• Organic Semiconductors
• Scanning Tunneling Microscopy
• Two-Photon Photoemission
• Chemistry

Statement dc:rights

• Copyright © is held by the author. Digital access to this material is made possible by the University Libraries, University of Arizona. Further transmission, reproduction or presentation (such as public display or performance) of protected items is prohibited except with permission of the author.

Language dc:language.iso

en_US

Handle dc:identifier.uri

http://hdl.handle.net/10150/321297

OAI identifier oai:identifier

oai:repository.arizona.edu:10150/321297