Jared Abramson
Approximately 250,000 metric tons of nuclear waste currently sit in short term storage around the world with the US accounting for over 90,000. Deep geologic repositories (DGRs) are widely considered the best solution to dispose/storge this waste. The general design of DGRs is widely agreed upon, but some specific aspects optimum design is still uncertain and understudied. One of these aspects is the cement that is used as containment and backfill in some DGR designs, including the design that was implemented in the US at Yucca Mountain until recently. My research focuses on studying different cement formulations to understand how the cement will contribute...
Duncan Reece
Hydrogen is being developed more and more as a sustainable fuel. The combustion of hydrogen produces no carbon emissions and it is suitable for use in gas turbines, internal combustion engines, and fuel cells. However, the primary source of hydrogen is fossil fuels. The focus of my research is developing new ultra-thin films with highly specific structures and properties to improve the efficiency and reaction kinetics of hydrogen production from water electrolysis. Yet, water electrolysis is still too energy-intensive and expensive to compete with current methods. Density functional theory has shown that the slow kinetics of the oxygen evolution reaction, the rate-limiting step of electrolysis, can...
Tharindu W. Fernando
I will use computational and theoretical approaches to understand and predict topological effects of materials in their optically excited states. Currently, I am wrapping-up an investigation on a novel interband index T for 2D systems (such as transition metal dichalcogenides). We showed that T may provide gauge-invariant excitonic optical selection rules and help characterize valley topology in excited states. Next, I will develop robust DFT-based computational schemes to calculate T in other materials beyond tight-binding frameworks. I will simultaneously study T in non-Hermitian systems; which are realistic quantum systems with gain and loss due to interactions with optical fields and environments. I am interested...
Jiayi Li
I will work on large-scale integration of renewable energy resources such as rooftop solar PV: specifically, I will develop state-of-the-art tools at the intersection of machine learning and power system control to safely and efficiently integrate distributed energy resources. A motivating application for me is the integration of solar PV into the distribution system. They can both create large and rapid voltage fluctuations, as well as correcting them using inverter interfaces. Optimizing the actions of inverters is complex and computationally very challenging. Machine learning can be very helpful in designing the controllers but due to the uncertainty and volatility of the system, existing methods do...
Yifei He
Conjugated polymers (CP), a solution-processable and mass-producible semiconducting material, are a promising candidate in the application of organic solar cells. One important factor that determines the light-electricity conversion efficiency of CPs is the morphology. My research will thus primarily investigate the method to control the microstructure of the thin films via accurate copolymerization. The ultimate goal of my project is to establish the knowledge about the relationship of molecular structure-morphology-optoelectronic performances, which contributes to the future design of high performance polymers in solar cells that could be mass manufactured. Advisor: Christine Luscombe - Materials Science & Engineering...
Madeleine Breshears
My research focuses on merging data science and machine learning techniques with functional scanning probe microscopy (SPM) to better understand energy materials. We are currently experiencing a convergence of advancement in both data science techniques and scanning probe microscopy resolution and functionality. I aim to take advantage of this confluence to evaluate the spatial heterogeneity of photovoltaic materials. SPM allows us to visualize surface photovoltage, charging rate, chemical composition, and morphology on the nanometer scale. These multimodal techniques produce incredibly dense, multidimensional data that naturally encourage the use of machine learning to extract meaningful information more efficiently. Specifically, I am working on using neural...
Daniel Zhou
Thermoelectric materials, or materials that can convert waste heat into electricity are promising sources for renewable energy. For a thermoelectric material to be efficient, it must have low thermal conductivity and high electrical conductivity. Prime candidates for these materials are Zintl phases which are semiconductors that can exhibit metallic conductivity due to the contributions of ionic and covalent character. Both the cationic and anionic sites of these compounds can be manipulated to tune the electronic and thermal properties. The Velian group has developed redox-active nanoclusters that can be tuned electronically with the addition of different transition metals. I plan on linking these nanoclusters with inorganic...
Ying Xia
The focus of my research will be interface-assisted solution-synthesis of two-dimensional metal-porphyrin monoatomic layers (2D-PML), which are of great interest due to the tunability of their properties. I will use two methods to synthesize metal-porphyrin monoatomic layer structures, one is the hydrothermal method, the other is the water-oil interface assisted method. AFM will be the main characterization method to analyze nucleation and growth mechanisms during the synthesis procedure. Then clean energy applications such as catalysts for hydrogen evolution and electrical capacitance will be studied. Advisor: Jim De Yoreo and Jun Liu - Materials Science & Engineering...
Julia White
Advances in energy storage are a critical aspect of the effort to convert the world to clean energy sources as electrification increases. For applications such as electric vehicles, lithium ion batteries are the best technology available but need to be improved upon further to meet energy density and power demands. Anode-less lithium batteries are extremely promising for drastically increasing energy density and rate capabilities, yet dendrite formation leading to rapid failure remain an obstacle in their implementation. My research will focus on designing ultrathin (<50 micron) 3D current collectors, altering both geometry and chemistry, and examining the mechanism of lithium electrodeposition. The findings will...
Xingyi Wang
Semiconductor crystals that behave exactly as researchers expect are rare, if nonexistent in nature or in lab. Local environment within crystals like defects or surface discontinuities may dominate the properties of semiconductor materials, and often these intractable local impurities limit the performance of clean energy harvest or generation devices like solar cells or LEDs. As part of a collaboration, my project takes a step towards understanding photon generation and loss mechanisms bottom-up by isolating and directly observing single defects within ZnO nanoparticles at atomic level, and correlating their optical properties with theoretical calculations based upon the local environment of single defects. If the observed...
Eden Tzanetopoulos
Lighting accounts for 15% of annual global energy consumption. Due to mounting concerns arising from anthropogenic climate change, there is an increased demand for lighting technologies with higher efficiencies and greater longevity. My research will focus on synthesizing colloidal nanocrystals of Mn4+-doped A2MF6 (A = K, Na, Cs; M = Ti, Ge, Zr) lattices to be used as red-emitting phosphors. These activator-host materials can act as an efficient red component of white LEDs due to their narrow-band ~630 nm emission. Mn4+-doped fluorides have recently been utilized in next-generation lighting technologies, but the nanoscale regime that affords synthetic tunability and narrow emission bandwidth has yet to...
Kathleen Snook
Electrically conductive metal–organic frameworks (MOFs) are important due to their applications in electrocatalysis, energy storage, and electronic devices. However, their synthesis is often poorly developed, resulting in small crystal sizes and a limited understanding of their physical properties. I hypothesize that a critical barrier to their synthesis is uncontrolled ligand oxidation, as conductive MOFs often contain air-sensitive catechol, o-phenylenediamine, and dithiolene building units. During this award period, I will examine the synthesis of π–d conjugated 2D frameworks, an important family of conductive MOFs, via controlled chemical oxidation in an inert atmosphere. I will optimize my synthetic parameters using a design of experiments approach, in...