Two-dimensional (2D) materials and heterostructures have attracted significant attention for a variety of nanoelectronic and optoelectronic applications. At the atomically thin limit, the material characteristics and functionalities are dominated by surface chemistry and interface coupling. Therefore, methods for comprehensively characterizing and precisely controlling surfaces and interfaces are required to realize...
This dissertation presents a comprehensive study of thin-film LiMn2O4 (LMO) cathodes applied in lithium ion batteries (LIBs). The primary aim was to establish fundamental understanding of the relationship between interfacial LMO chemistry/electrochemistry and its detrimental drawback, i.e. fast capacity fade over long term cycling, and then develop effective mitigation methods....
Semiconductor nanowires, such as group IV and III-V nanowires, shows distinct electrical, optical and mechanical properties from their bulk counterparts due to their nanoscale size and 1-D morphology. For example, the quantum confinement effect modulates the band gap of a semiconductor nanowire when its diameter approaches or below the exciton...
The advancement of nanotechnology is at least partially dependent on the ability to synthesize and arrange complex nanostructures on a substrate. Nanolithography, or the patterning of materials at the sub-micrometer length-scale, has been traditionally performed using a number of methods such as conventional photolithography, ion-beam etching, and electron-beam lithography. While...
High performance polymers and their composites have wide ranging application in advanced and emerging material systems. The macroscale performance of these advanced materials is often defined by interfaces that induce nanoscale changes in the microstructure or molecular conformations (termed the ‘interphase’) of the polymer. Atomic force microscopy (AFM) is an...
Ordered arrays of metallic nanoparticles (NPs) are a promising platform for technological applications and fundamental investigations due to their ability to excite surface lattice resonances (SLRs). SLRs can support extremely high local electric fields that have been used to realize exotic physical phenomena. The open cavity architecture lends itself to...
This thesis centers around the development and application of novel high throughput lithography tools. These advances help: 1) establish the field of nanocombinatorics, where massive libraries (termed megalibraries) of materials can be prepared in a positionally encoded manner and then screened for functional activity, and 2) advance stereolithographic 3D printing...
Non-planar and curved architectures of otherwise flat 2D materials present an important paradigm for nanoscale analysis and design of emergent material properties. Atomically-thin transition metal dichalcogenides (TMDs) have emerged at the forefront of the 2D materials field in recent years largely due to their attractive and tunable chemical, optical, and...
Materials that exist as well-defined individual entities at the nanoscale typically have properties that sets them apart from their bulk form. Consequently, there has been much time and effort invested in developing new well-defined nanoscale entities, but few attempts to assemble them into bulk materials. On the other hand, there...
Colloidal crystal engineering with DNA offers new opportunities for materials scientists to build and program the structures of superlattices beyond what can be accomplished in Nature with atomic crystal lattices. Thus far, such materials primarily have been studied for their optical properties due to the insulating nature of the DNA...
The idea that structure determines the properties of a material is a powerful concept in chemistry and in all fields in which chemistry is important, including engineering, medicine, and materials science. My research aims to better understand the structure-property relationships of a class of materials known as metal–organic frameworks (MOFs)....
The ability to control the crystalline ordering and morphology of polymeric nanomaterials is a grand challenge in the field of materials science, which could enable the development of functional materials able to solve long-standing problems in renewable energy and medicine. In this work, we explore a combination of supramolecular chemistry...
Nanomaterials present an exciting landscape of innovation at length scales below 100 nm, wherein controllable synthesis and materials metrology have led to tunable structure-property relationships and next-generation products. The disruptive field of nanotechnology is poised to capitalize upon the exotic chemistry and physics of these nanomaterials to enable more efficient...
Multimetallic nanoparticles represent an important class of electrocatalysts which are critical for many energy and environmental applications including fuel cells, hydrogen production, and greenhouse gas elimination. The properties of these nanoparticles depend on their composition, size, shape, and structure. Therefore, developing new strategies which provide a high level of control...
Scalable processing of well-defined interfaces is key not only for wider application of two-dimensional (2D) materials in technology but also for improved fundamental understanding. Atomic layer deposition has useful characteristics, especially self-limited growth at low temperatures, that make it well suited for the production of uniform interfaces. Related processes, such...
As demonstrated by efforts in graphene commercialization, scalable synthesis and high-quality material availability are primary limiting factors for the realization of technologies based on two-dimensional (2D) materials. Thus, in considering the fate of emergent 2D materials such as the metal chalcogenides, the challenge of scalable synthesis is a highly relevant...
Nanotechnology research broadly encompasses the exploration of the unique chemical,optical, electronic, or biological properties of materials with dimensions < 1 µm. Inorganic
nanoparticles are one such class of materials, with properties that are exceptionally sensitive to
particle size and structure. This is especially evident in the field of heterogeneous chemical...