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...
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...
Yangwei Shi
I will focus on fabrication and characterization of organic-inorganic halide perovskite solar cells which are regarded as a promising photovoltaic technology. My projects include passivation of mixed cation mixed halide wide-bandgap perovskite, aiming to improve the photoluminescence quantum efficiency of perovskite and to achieve a higher open-circuit voltage that approaches the theoretical limit. In addition, I will focus on developing a solution processed recombination layer with matched refractive index and good conductivity for tandem perovskite/silicon solar cell. Based on the low defect density of wide bandgap perovskite and solution processible recombination layer, the efficiencies of tandem perovskite/silicon solar cells can be further increased. Advisor: David...
Christine Morrison
Conjugated polymers are touted for their electronic and photonic properties, and have been shown to have significant applications in light-harvesting and storage. Much research has already been done showing the plethora of applications for conjugated polymers, but there has been considerably less work involving conjugated cyclic polymers. My research is focused on creating an optimized initiator for ring expansion metathesis polymerizations (REMP) for use in the synthesis of conjugated cyclic polymers. Ring expansion polymerizations are a favorable way to approach the production of cyclic polymers as they provide better control over molecular weight, effective conjugation length, and long-range morphology of the polymer. Using REMP...
Yuhuan Meng
The goal of my research is to predict the degradation of encapsulated perovskite films and devices. Perovskite solar cells (PSCs) show potential for ultra-low manufacturing cost with high power conversion efficiency. However, the commercialization of PSCs is still uncertain given concerns about their stability. Previously, we showed how to predict the degradation of diffusion length in non-encapsulated MAPbI3 films over an extremely wide range of environment conditions using machine learning (ML). However, encapsulation is necessary for long service lifetimes. During the period of the award, I will collect a large dataset of degradation kinetics of encapsulated MAPbI3 and (FA,Cs)Pb(I,Br)3 perovskite films that includes in-situ optical transmittance along with video...
Inhwan Ko
My research focuses on the consequences and origins of various local renewable energy conflicts. A growing number of local communities around the world are facing land-use conflicts surrounding renewable energy facilities, and they are creating barriers to the national clean energy transition. For instance, local renewable energy conflicts, if not properly resolved, can derail local renewable energy projects, translate into unfavorable electoral outcomes for clean energy transition policies, and contribute to the diffusion of policy barriers to renewable energy facilities. To understand these consequences, however, one must investigate why local renewable energy conflicts unfold in the first place. NIMBY (not-in-my-back-yard) explanation provides only a...
Lixin Lu
Doped metal-halide perovskites CsPbX3 (X=Cl, Br or I) nanocrystals (NCs), which combine the desirable broadband absorptive properties of perovskite semiconductors with the richly tunable color emission profiles of sensitized metal ion dopants, have a great potential in the application of high-efficiency solar cells, LEDs, and lasers. Successful doping of various trivalent lanthanide ions (or rare earth ions, RE) into colloidal perovskite NCs has been recently reported. For example, ytterbium (Yb3+)-doped CsPbX3 exhibits over 100% photoluminescence quantum yields (PLQY) as a result of picosecond quantum cutting process, indicating its opportunities to serve as downconverters in solar-energy-conversion technologies. Despite of the experimental evidence, the electronic structural...
Nada Naser
My research focuses on the integration of solid binding peptides (SBPs) within the framework of proton-transporting transmembrane proteins to create new devices and materials that will enable next-generation energy systems. SBPs are combinatorially selected peptides that bind with high affinity to inorganic materials. By genetically inserting these peptides at various sites of functional transmembrane proteins (e.g., light-activated ion transporters), and by exploiting emerging techniques to isolate and stabilize the resulting chimera in polymeric nanoparticles, I intend to fabricate new devices to control charge transfer and chemical potential across interfaces in response to light illumination. Additionally, I am interested in developing responsive materials in which...
Xiaofeng Xiang
Photovoltaic devices are important for the renewable clean energy system. Today, silicon-based solar modules keep dominating the market, but various emerging techniques based on thin-film inorganic semiconductors are rapidly developing. Among thin-film technologies, chalcopyrite Cu(In, Ga)Se2 (CIGS) shows excellent light conversion efficiency. The primary goal of my research is to develop modeling tools for design and optimization of CIGS fabrication and device operation processes. To achieve this goal, the first step is to understand the fundamental chemical reactions or physical phenomenons happening during manufacturing processes. Next, I would apply first principle calculations and use device simulation software to understand thermodynamic or kinetic aspects of the materials. Finally,...
Preetham Paul Sunkari
The overarching goal of my research is to pioneer new methods to forecast the degradation of perovskite semiconductors and photovoltaic devices. Perovskite solar cells (PSC) showed a rapid increase in power conversion efficiencies from 14% to 25.2% in just seven years. But their poor stabilities have questioned the practicality of their operational deployment. To study the stability of PSCs, I plan to investigate material-level optoelectronic quality changes in perovskite films under different thermal, light, oxygen, and humidity stresses through in-situ photoluminescence (PL) and dark field (DF) microscopy, photoconductivity, and film transmittance measurements. Based on trends in this data, the dominating degradation mechanisms and the...
Margherita Taddei
Today, one of the most pressing issues for our society is to meet the constant increase in energy demand with sustainable alternatives. For this reason, scientists are looking for clean and renewable energy sources. In the solar energy field, perovskite solar cells (PSCs) have attracted a lot of attention due to their incredible increase in efficiency from 3.8% to 25.2% in only 10 years of research. The main issues encountered in PSCs are the presence of toxic cations, low efficiency, and stability. Therefore, for future commercialization, it is necessary to develop eco-friendly, stable, and efficient perovskite materials. My work focus on finding new solution-processable environmentally-friendly...