During the past thirty years considerable efforts have been made to design the synthesis and the study of molecular semiconductors. Molecular semiconductors - and more generally molecular materials - involve interactions between individual subunits which can be separately synthesized. Organic and metallo-organic derivatives are the basis of most of the molecular materials. A survey of the literature on molecular semiconductors leaves one rather confused. It does seem to be very difficult to correlate the molecular structure of these semiconductors with their experimental electrical properties. For inorganic materials a simple definition delimits a fairly homogeneous family. If an inorganic material has a conductivity intermediate between that of an 12 1 1 3 1 1 insulator « 10- n- cm- ) and that of a metal (> 10 n- cm- ), then it is a semiconductor and will exhibit the characteristic properties of this family, such as junction formation, photoconductivity, and the photovoltaic effect. For molecular compounds, such simplicity is certainly not the case. A huge number of molecular and macromolecular systems have been described which possess an intermediate conductivity. However, the various attempts which have been made to rationalize their properties have, more often than not, failed. Even very basic electrical properties such as the mechanism of the charge carrier formation or the nature and the density ofthe dopants are not known in detail. The study of molecular semiconductor junctions is very probably the most powerful approach to shed light on these problems.

This thesis targets molecular or organic spintronics and more particularly the spin polarization tailoring opportunities that arise from the ferromagnetic metal/molecule hybridization at interfaces: the new concept of spinterface. Molecular or organic spintronics is an emerging research field at the frontier between organic chemistry and spintronics. The manuscript is divided into three parts, the first of which introduces the basic concepts of spintronics and advantages that molecules can bring to this field. The state of the art on organic and molecular spintronics is also presented, with a special emphasis on the physics and experimental evidence for spinterfaces. The book’s second and third parts are dedicated to the two main experimental topics investigated in the thesis: Self-Assembled Monolayers (SAMs) and Organic Semiconductors (OSCs). The study of SAMs-based magnetic tunnel nanojunctions reveals the potential to modulate the properties of such devices “at will,” since each part of the molecule can be tuned independently like a “LEGO” building block. The study of Alq3-based spin valves reveals magnetoresistance effects at room temperature and is aimed at understanding the respective roles played by the two interfaces. Through the development of these systems, we demonstrate their potential for spintronics and provide a solid foundation for spin polarization engineering at the molecular level.

Printed Organic And Molecular Electronics was compiled to create a reference that included existing knowledge from the most renowned industry, academic, and government experts in the fields of organic semiconductor technology, graphic arts printing, micro-contact printing, and molecular electronics. It is divided into sections that consist of the most critical topics required for one to develop a strong understanding of the states of these technologies and the paths for taking them from R&D to the hands of consumers on a massive scale. As such, the book provides both theory as well as technology development results and trends.

Molecular Beam Epitaxy (MBE): From Research to Mass Production, Second Edition, provides a comprehensive overview of the latest MBE research and applications in epitaxial growth, along with a detailed discussion and 'how to' on processing molecular or atomic beams that occur on the surface of a heated crystalline substrate in a vacuum. The techniques addressed in the book can be deployed wherever precise thin-film devices with enhanced and unique properties for computing, optics or photonics are required. It includes new semiconductor materials, new device structures that are commercially available, and many that are at the advanced research stage. This second edition covers the advances made by MBE, both in research and in the mass production of electronic and optoelectronic devices. Enhancements include new chapters on MBE growth of 2D materials, Si-Ge materials, AIN and GaN materials, and hybrid ferromagnet and semiconductor structures. - Condenses the fundamental science of MBE into a modern reference, speeding up literature review - Discusses new materials, novel applications and new device structures, grounding current commercial applications with modern understanding in industry and research - Includes coverage of MBE as mass production epitaxial technology and how it enhances processing efficiency and throughput for the semiconductor industry and nanostructured semiconductor materials research community

Written in the perspective of an experimental chemist, this book puts together some fundamentals from chemistry, solid state physics and quantum chemistry, to help with understanding and predicting the electronic and optical properties of organic semiconductors, both polymers and small molecules. The text is intended to assist graduate students and researchers in the field of organic electronics to use theory to design more efficient materials for organic electronic devices such as organic solar cells, light emitting diodes and field effect transistors. After addressing some basic topics in solid state physics, a comprehensive introduction to molecular orbitals and band theory leads to a description of computational methods based on Hartree-Fock and density functional theory (DFT), for predicting geometry conformations, frontier levels and energy band structures. Topological defects and transport and optical properties are then addressed, and one of the most commonly used transparent conducting polymers, PEDOT:PSS, is described in some detail as a case study.

The extended and revised edition of this textbook provides essential information for a comprehensive upper-level graduate course on the crystalline growth of semiconductor heterostructures. Heteroepitaxy is the basis of today’s advanced electronic and optoelectronic devices, and it is considered one of the most important fields in materials research and nanotechnology. The book discusses the structural and electronic properties of strained epitaxial layers, the thermodynamics and kinetics of layer growth, and it describes the major growth techniques: metalorganic vapor-phase epitaxy, molecular-beam epitaxy, and liquid-phase epitaxy. It also examines in detail cubic and hexagonal semiconductors, strain relaxation by misfit dislocations, strain and confinement effects on electronic states, surface structures, and processes during nucleation and growth. Requiring only minimal knowledge of solid-state physics, it provides natural sciences, materials science and electrical engineering students and their lecturers elementary introductions to the theory and practice of epitaxial growth, supported by references and over 300 detailed illustrations. In this second edition, many topics have been extended and treated in more detail, e.g. in situ growth monitoring, application of surfactants, properties of dislocations and defects in organic crystals, and special growth techniques like vapor-liquid-solid growth of nanowires and selective-area epitaxy.

The purpose of this book is to provide the reader with essential keys to a unified understanding of the rapidly expanding field of molecular materials and devices: electronic structures and bonding, magnetic, electrical and photo-physical properties, and the mastering of electrons in molecular electronics.

The first advanced textbook to provide a useful introduction in a brief, coherent and comprehensive way, with a focus on the fundamentals. After having read this book, students will be prepared to understand any of the many multi-authored books available in this field that discuss a particular aspect in more detail, and should also benefit from any of the textbooks in photochemistry or spectroscopy that concentrate on a particular mechanism. Based on a successful and well-proven lecture course given by one of the authors for many years, the book is clearly structured into four sections: electronic structure of organic semiconductors, charged and excited states in organic semiconductors, electronic and optical properties of organic semiconductors, and fundamentals of organic semiconductor devices.

Charge Transport in Organic Semiconductors, by Heinz Bässler and Anna Köhler. Frontiers of Organic Conductors and Superconductors, by Gunzi Saito and Yukihiro Yoshida. Fullerenes, Carbon Nanotubes, and Graphene for Molecular Electronics, by Julio R. Pinzón, Adrián Villalta-Cerdas and Luis Echegoyen. Current Challenges in Organic Photovoltaic Solar Energy Conversion, by Cody W. Schlenker and Mark E. Thompson.- Molecular Monolayers as Semiconducting Channels in Field Effect Transistors, by Cherie R. Kagan. Issues and Challenges in Vapor-Deposited Top Metal Contacts for Molecule-Based Electronic Devices, by Masato M. Maitani and David L. Allara. Spin Polarized Electron Tunneling and Magnetoresistance in Molecular Junctions, by Greg Szulczewski.