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Full-Text Articles in Nanoscience and Nanotechnology

The Optoelectronic Properties Of Surface-Modified Semiconductor Nanocrystal Solids, Earl D. Goodwin Jan 2015

The Optoelectronic Properties Of Surface-Modified Semiconductor Nanocrystal Solids, Earl D. Goodwin

Publicly Accessible Penn Dissertations

Colloidal semiconductor nanocrystals have emerged as fascinating new materials and gained interest in the last 30 years because of their size, shape, and compositionally tunable electronic and optical properties as well as their potential to serve as artificial atoms. Challenges and opportunities have arisen when assembling nanocrystals into nanocrystal solids for electronic and optoelectronic applications, largely because of the significant influence of nanocrystal surface chemistry on the electronic, optical, and structural properties of nanocrystal solids. In order to assemble nanocrystal solids for high performance devices, we must understand and be able to control the effects of nanocrystal surface organic capping ...


Designing Nanomaterials For Electronic And Optoelectronic Devices Through Charge Carrier Control, Soong Ju Oh Jan 2014

Designing Nanomaterials For Electronic And Optoelectronic Devices Through Charge Carrier Control, Soong Ju Oh

Publicly Accessible Penn Dissertations

Colloidal semiconductor nanocrystals (NCs) have been shown to be promising materials for electronic and optoelectronic device applications because of their unique size-dependent properties and low-cost solution processability. However, the integration of these materials into devices has been challenging due to a lack of available methods to: 1) accurately control charge carrier statistics, such as majority carrier type and concentration, and carrier mobilities, and 2) efficiently passivate surface defects inherent in NC materials arising from their high surface-volume ratio.

In this thesis, we study the fundamental physics of charge carriers paramount for device application. Then, we introduce several measurement techniques to ...


Directed Synthesis And Doping Of Wide Bandgap Semiconducting Oxide Nanocrystals, Thomas Ross Gordon Jan 2013

Directed Synthesis And Doping Of Wide Bandgap Semiconducting Oxide Nanocrystals, Thomas Ross Gordon

Publicly Accessible Penn Dissertations

Wide bandgap semiconducting oxide nanocrystals are a useful class of materials with high stability and numerous useful properties. In the field of catalysis, high surface area oxides are commonly used as catalytic supports and have been found to be photocatalytically active for the production of renewable fuels. Ultra high vacuum studies of single crystals indicate that the surface structure and faceting of oxides dramatically influence their catalytic properties. For plasmonics applications, degenerately doped oxide nanocrystals may act as low-loss substitutes for metals, but little is known regarding the influence of particle shape or assembly on their optical response. With the ...


Understanding Molecular Chemistry Of Nanocrystals And Nanostructures: Precursor, Ligand, And Surface Chemistry, Weon-Kyu Koh Aug 2011

Understanding Molecular Chemistry Of Nanocrystals And Nanostructures: Precursor, Ligand, And Surface Chemistry, Weon-Kyu Koh

Publicly Accessible Penn Dissertations

The aim of this dissertation is to understand the molecular chemistry of nanomaterials and to correlate their structures to their functions. The first part of this dissertation explores how we can use precursor chemistry to develop a synthetic approach to novel structures of nanomaterials. There will be a demonstration of morphology control in lead chalcogenide nanocrystals following an investigation of the precursor chemistry which gives valuable information on precursor decomposition during the crystal growth. At the same time, there will be a discussion about how we can understand structure-dependent properties of nanomaterials using advanced spectroscopic techniques. Well-established synthetic approaches discussed ...