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...
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...
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...
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...
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...
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...
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...
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...