At its core, the purpose of microscopy is to make objects and their underlying structures visible under high magnification. With the remarkable progress of electron microscopy, the sub-micron “high” magnification of light microscopy has been completely refashioned to encompass subatomic length scales. Unfortunately, higher-magnification does little to negate existing interpretability...
Plasmonic nanoparticles have very large absorption cross sections and can concentrate the local density of photon states on the nano scale. When they are coupled to molecules or semiconductor nanocrystals and form different hybrid nanostructures, various light-matter interaction processes can be significantly enhanced or manipulated, including optical responses like fluorescence...
Electrochemical devices play a vital role in the efforts towards a sustainable green future. Solid acid based electrochemical cells, employing super protonic CsH2PO4 (CDP) as the electrolyte component, offer unique application advantages due to their operability at intermediate temperatures 250°C. At these temperatures, one can achieve improved reaction kinetics over...
Nanocarriers are drug delivery vehicles that have at least one dimension at the nanoscale (10-9 m). Engineering the nanocarrier surface is a strategy for targeting drug delivery to specific cell types to enhance efficacy and minimize side effects. A useful analogy is to consider how the chassis of an automotive...
Semiconductor nanocrystals possess unique photophysical properties that make them desirable for many optoelectronic applications such as photovoltaics, LEDs, and quantum computing. When the size of a semiconductor is reduced to below the excitonic Bohr radius of the material, its carriers becomes quantum confined resulting in drastic changes to optical, electronic,...
Materials science has been central to human advancement since time immemorial. There has always been curiosity around studying the processes required to extract materials, examine their structure, and ultimately tailor their properties to meet human needs. Over the last few centuries, the ability to tailor material properties was driven by...
Engineering heat transport in materials is essential for thermal management in a wide range of technologies, from batteries to thermoelectrics. Materials host a wide spectrum of heat-carrying phonons, which vary in their frequency, spatial extent, and degree of plane-wave character. This diversity in phonon properties leads to complex behavior, especially...
The demand for low cost, unconventional electronics requires new materials with unique characteristics that the traditionally used silicon-based technologies cannot provide. Metal oxide semiconductors, such has amorphous indium gallium zinc oxide (a-IGZO), have made impressive strides as alternatives to amorphous silicon for electronics applications. However, to achieve the full potential...
This dissertation explores ways to utilize physical parameters at the nanoscale interface to control the properties of mixed-dimensional heterojunctions (MDHJs). MDHJs combine the desirable properties of different classes of low-dimensional nanomaterials (materials that are quantum confined in at least one dimension). While MDHJs have achieved superlative performance for a variety...
Two-dimensional (2D) hybrid halide perovskites have been the response to their exciting but woefully unstable 3D counterparts. These 2D perovskites have been shown to have respectable stabilities as photovoltaic absorbers, yet they lag behind the 3D perovskites in terms of efficiency. With the need to catch up to the efficiencies...
A framework is developed that models point defect diffusion and interaction with pre-existing microstructures during irradiation, including defect-defect interactions and defect sinks. This framework uses a modified diffusion potential that includes not only defect concentration, but also intrinsic stresses from the pre-existing microstructure. Various microstructures are studied in {Fe} by...
The highly flexible nature of 2D materials has led to them becoming fundamental building blocks for achieving novel device physics and potential breakthroughs in practical technologies. 2D layers can be interfaced in a wide array of methods with themselves, other 2D layered materials, or materials of entirely different type or...
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...
Nanomaterials are increasingly incorporated in modern day life, from the biogenic viruses that cause pandemics and the mineral crystallites embedded alongside collagen in our bones, to the anthropogenic nanomaterials that are small but powerful components of sunscreen and paint, swimming pool algaecides and wound dressings, cancer treatments, bicycle frames, and...
Metallic conductivity and broken inversion symmetry were long thought to be contraindicated properties, under the assumption that long-range Coulombic interactions (screened by free charge carriers) were necessary for coordinated polar displacements. Within the past decade, the discovery of polar metals has prompted a rethinking of the relationship between metallicity and...
This thesis describes the synthesis and photophysical characterization of low-dimensionalmaterials—including thin-film semiconductors, colloidal quantum dots, and molecules—with the
broader motivation of integrating them into mixed-dimensional heterostructures with novel
responses to external stimuli. Due to their high surface area to volume ratio and incomplete
dielectric screening, mixed-dimensional heterostructures have high sensitivity...
Soft materials in nature are formed through programmed self-assembly of biomolecules to create complex architectures and optimized physical properties. It is therefore a key challenge in biomaterials science and engineering to understand the principles that govern the structure and properties of such materials, and the interactions between their different components....
Nanoparticle synthesis is capable of producing particles with any combination of structure, chemistry, size, shape, and surface. All of the different combinations of these physical properties can produce nanoparticles with almost countless materials properties suited for many applications. Given this interest in using nanoparticles in so many different fields, including...
One of the central challenges in solid-state chemistry is synthetic control over structure. Owing to limited reactivity of Pb with transition metals at ambient pressure and high temperature as well as the variety of properties that emerge from the few known binary transition-metal–Pb compounds, this research focuses on accessing and...
Over the last few years, there has been a transition away from traditional engineering materials to new advanced materials that exhibit complex architectures with improved mechanical properties. Most of the inspiration for these new materials comes from nature, where organisms have evolved an immense variety of macro and nanoscale shapes...