Dissertation/Thesis Abstract

Two-Dimensional Nanoparticle-Molecule Arrays for Molecular Electronics and Thermoelectrics
by McCold, Cliff E., Ph.D., University of California, Davis, 2018, 135; 10687141
Abstract (Summary)

Nanoparticle-molecule arrays are a versatile material platform for electronic, optical, chemical, and thermal applications, as well as fundamental transport investigations in artificial solids. These structures allow simple macroscopic access to nanoscale physical phenomenon by leveraging the conductivity of nanoparticles and the wide variety of interesting surface functionalizations provided by molecular capping layers. This dissertation begins with a brief summary of the state of the field of research in nanoparticle arrays, and the mention of several challenges to be addressed. The background covers fundamental physical mechanisms and models in synthesis, self-assembly, charge transport, and thermoelectricity useful for interpreting the subsequent chapters. Chapter 3 investigates the role of two-dimensonal array structure on direct current charge transport, distinguishing between “macrostructural” and “microstructural” effects. Chapter 4 examines the effect of ligand exchange on conductivity and uses a bond percolation model to enable prediction of ligand exchange efficiencies, which are supported by Monte Carlo hopping simulations. Chapter 5 presents thermoelectric measurements of nanoparticle-molecule arrays incorporating five conjugated heteroacene molecules. A crossover in the sign of the majority charge carrier seen in thermoelectric and Hall effect measurements is understood through the position of molecular orbitals relative to the nanoparticle Fermi level, and a technique to further maximize the thermoelectric potential of nanoparticle-molecule arrays is discussed. Ultimately, the charge transport properties of nanoparticle-molecule arrays are understood by looking at array structure, molecular size, and molecular energy levels.

Indexing (document details)
Advisor: Hihath, Joshua
Commitee: Faller, Roland, Kuhl, Tonya
School: University of California, Davis
Department: Materials Science and Engineering
School Location: United States -- California
Source: DAI-B 79/09(E), Dissertation Abstracts International
Subjects: Electrical engineering, Nanotechnology, Materials science
Keywords: Artifical solids, Charge transport, Molecular electronics, Nanoparticles, Thermoelectric, Tunneling
Publication Number: 10687141
ISBN: 978-0-355-96924-5
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