WE-MSE Colloquium: Lee Semiatin, AFRL R&D on Inertia Friction Welding of Nickel-Base Superalloys
This will be a joint WE-MSE Colloquium held at 3:00 p.m. in 264 MacQuigg Labs.
An overview of recent R&D performed by AFRL (some in conjunction with OSU) in the area of inertia friction welding (IFW) of gamma-prime-strengthened, nickel-base superalloys will be presented. This work has focused on three major areas – process mechanics, material behavior during IFW, and the joining of dissimilar alloys. Two of the key elements of the IFW process consist of friction between the mating workpieces (thereby heating the interface) and energy losses in the mechanical system per se. Methods to quantify the coefficient of friction and overall machine efficiency will be described. Second, methods to quantify transient flow behavior and the kinetics of the dissolution of gamma prime will be described. These techniques include special methods to investigate the interaction of dynamic microstructural changes and plastic flow. Last, the selection of process parameters for joining superalloys with different solvus temperatures/plastic-flow responses will be addressed. One particular method to reduce non-uniform metal flow, which involves local preheating, will be highlighted.
Dr. Lee Semiatin is Senior Scientist (ST), Materials Processing/Processing Science in the Air Force Research Laboratory, Materials and Manufacturing Directorate. He received a BES in Mechanics from Johns Hopkins University and MS and PhD degrees in Metallurgy and Materials Science from Carnegie Mellon University.
Dr. Semiatin worked at Battelle Memorial Institute from 1978 to 1991. Here, he conducted and directed programs for a wide range of government and industry clients. A large portion of his government-sponsored work was for the Air Force Materials Laboratory and Air Force Office of Scientific Research (AFOSR). This included basic studies of the workability of difficult-to-process aerospace alloys, the fundamentals of material behavior during deformation processing, and various National Aerospace Plane (NASP) – related programs. Both the government as well as industrial programs involved a major component of technology transfer and thus working with a wide range of manufacturing companies.
In June 1991, Dr. Semiatin joined the Materials and Manufacturing Directorate as Senior Scientist for Materials Processing/Processing Science. Under his direction, R&D has been conducted in four major areas: advanced metallic, intermetallic, and nanocrystalline alloys; conventional titanium, nickel, and aluminum alloys; novel processes; and advanced modeling tools for the prediction of microstructure, texture, and damage evolution during deformation and solidification processing. The integration of various modeling, characterization, and input-data tools that underlie ICMSE form a key part of current research. These efforts have led to the development of various new forging, extrusion, and rapid heat treatment processes – some of which are utilized on a production basis. In addition, he consults regularly with a number of manufacturing vendors on material-processing problems which impact Air Force systems.
Dr. Semiatin has authored/co-authored over 400 journal papers in the area of materials processing. He has also written/edited 18 books/handbooks/conference proceedings, 27 limited distribution reports, and holds 9 patents.
MSE Colloquium: Siddhartha Pathank, Probing Nanoscale Damage Gradients in Irradiated Metals Using Nano-mechanical Test Techniques
Materials with modified surfaces – either as a consequence of a graded microstructure, or due to an intentional alteration of the surface – are of increasing interest for a variety of applications ranging from enhanced wear and corrosion resistance, superior thermal and biomedical properties, higher fracture toughness, and reduced stress intensity factors etc. In some cases, such gradations at the surface may also be caused unintentionally as a consequence of the service life of the material, such as in wear applications or irradiated materials which show varying degrees of radiation damage that change with depth, location of radiation source, etc. Quantifying the resulting property gradations poses a significant challenge, especially when the changes occur over small (sub-micrometer) depths. The first half of this presentation will focus on a novel indentation approach which, together with the corresponding local structure information obtained from electron backscatter diffraction (EBSD), allows us to probe nanoscale surface modifications in solid materials and quantify the resulting changes in its mechanical response. Using tungsten as a specific example we discuss the capabilities of spherical nanoindentation stress-strain curves, extracted from the measured load-displacement dataset, in characterizing the elastic response, elasto-plastic transition, and onset of plasticity in ion-irradiated tungsten under indentation, and compare their relative mechanical behavior to the unirradiated state.
Time permitting we will also use a series of examples to show the capabilities of our nanoindentation techniques in (a) characterizing the local indentation yield strengths in individual grains of deformed polycrystalline metallic samples and relating them to increases in the local slip resistances, (b) correlating the stored energy differences of individual grains to their Taylor factors as a function of imposed cold work, and (c) understanding the role of interfaces (grain boundaries) in the deformation of a polycrystalline sample.
The second part of this presentation will focus on alternate testing techniques of miniaturized structures at these lower (micron to nanometer) length scales. In particular we look at utilizing a combination of nanoindentation, in-situ SEM compression testing of micro-pillars, and the recently developed in-situ SEM fracture toughness testing of 3 point bend micro-beams on multilayered nano-composites to evaluate their deformation mechanisms. These two-phase nanolayered composites have individual layer thicknesses varying from microns down to 1-2 nm, where one of the constituent phases has low ductility (such as a metal-ceramic Al-TiN, Cu-TiN, or a HCP-BCC Mg-Nb nanocomposite), with the final goal of enhancing both the strength and ductility of the system.
Prof. Siddhartha (Sid) Pathak is an assistant professor in the Chemical and Materials Engineering department at the University of Nevada, Reno (UNR) since Fall 2015. Before joining UNR he was a Director’s Postdoctoral Fellow at Los Alamos National Laboratory (LANL). His research interests are in the field of nanomechanics, particularly in developing novel experimental test strategies for mechanical testing of nano-structured materials. He has co-authored 30 peer reviewed articles and 2 book chapters in various scientific journals. He has received numerous scientific awards based on his work including the 2010 W.M. Keck Institute for Space Studies Prized Postdoctoral Fellow in Materials Science at Caltech and a finalist nomination for the Journal of Materials Science Robert W. Cahn Best Paper Prize for 2012 (the “Cahn Prize”).
MSE Colloquium: Sridhar Narasi, Long Term Performance Assessment of Materials
Structural materials are required to operate over long periods of time, often well past their original design lives. Failures of materials occur due to the accumulation of almost imperceptible changes in the materials, interfaces, and the surrounding environment. Much research is done to analyze the mechanisms of the failures, design test methods, build models, and develop standards to prevent future failures of the types that have already been observed. We have developed and honed our analytical skills.
However, we have been spectacularly poor in anticipating failure modes that have not already happened (the so called “unknown unknown” problems). For example, near-neutral pH SCC of carbon steel was not known until the 1990’s after such failures occurred in Canadian pipelines. SCC of steels in ethanol was not anticipated until failures occurred in the 20000’s. The list is long and depressing. What the decision makers need to know is not only what our research results mean today, but what it will mean tomorrow. This requires not only analytical, but also synthesis skills (and a lot of courage). We need to know how to systematically synthesize diverse sources of knowledge in a predictive framework. Since both knowledge of mechanisms and data are uncertain, the predictive framework is necessarily probabilistic.
This talk will focus on methods to develop probabilistic assessments of failure of materials using a hierarchical approach of fundamental, process level, and abstracted models. The talk will first discuss long-term localized corrosion prediction of stainless steels and Ni-base alloys using a combination of experimental and modeling approaches for a diverse set of applications. Next, the talk will extend the approach to stress corrosion cracking of these alloys in oil and gas applications. The lessons learned from applying this approach will be presented. Finally, an approach to synthesize knowledge using Bayesian networks will be presented.
Dr. Sridhar is a Vice President of DNV and the Director of Materials Program in DNV Strategic Research & Innovation. He also serves as an Adjunct Professor at The Ohio State University, Materials Science & Engineering Department. His main technical interests involve risk management of corrodible systems, advanced materials applications in diverse industries, and carbon dioxide utilization technologies. Prior to joining DNV in 2007, he worked at Southwest Research Institute, San Antonio, Texas for 18 years as a Program Director, where he was involved in developing life-prediction methods and sensors for nuclear waste disposal, pipelines, DoD systems, and NASA. From 1981 through 1989, he worked at Haynes International, Kokomo, Indiana as a group leader, where he was involved in the development of advanced Ni and Co-base alloys. He obtained a Ph.D. from University of Notre Dame in 1980.
Dr. Sridhar has published over 180 papers and book chapters. He is a Fellow of NACE International and the recipient of NACE Technical Achievement award. He is also the recipient of the Vaaler award, the Guy Bengough award, the R&D 100 award, the Edward C. Greco International Corrosion Council Award and the Tech Columbus award. He is currently serving as an Associate Editor of Corrosion Journal and Corrosion Engineering Science & Technology journal. He has received a number of patents in the areas of advanced alloys, sensors, fuel cells, and CO2 conversion process.
MSE Colloquium: Ke Sun, Materials and Systems at Nanoscale for Carbon-free Energy Future
Breaking our fossil fuel habit in one step
Extensive use of fossil fuels to support the growth of economy and population causes serious impacts to the environment, damage to public health, habitat loss, and climate change. Efficiently harvesting renewable energies like solar and wind is capable to meet our energy demand with a minimized environmental impact. However, storing intermittent renewable energies based on current battery technologies is either extremely expensive or has low energy density to scale up. Solar energy conversion and its direct storage in chemical fuels (solar fuel) using only water and air have received recent attentions worldwide, which could fully unlock the potential of solar energy and deep decarbonize our energy system by providing a grid-level storage of solar energy. Chemical fuels produced from this technology can be stored and transported through existing infrastructures, e.g., gas tanks and pipelines. Fuels then can be directly used in gas turbines for centralized power plants, internal combustion engines for heavy-duty vehicles that cannot be electrified, and fuel cells for energy generation in isolated areas.
In artificial photosynthesis based on semiconductor photoelectrochemistry, the production of chemical fuels generally requires the coupling of semiconductors with electrocatalysts where electrical charges are generated, separated and transferred for multi-electron chemical reactions, as well as the pairing of light-absorbing materials with optimum bandgap combinations. The development of such proof-of-concept systems has been hindered in part by the lack of semiconducting materials that can provide low-cost, efficiency and stability simultaneously in a corrosive environment, typically either strong acid or base. In this talk, I will present our recent progress in the development of stable and efficient solar fuel systems for sustainable H2 generation from splitting water and formate production from CO2 reduction. I will then introduce the concept of artificial N2 photo-fixation for sustainable NH3 production, a promising candidate for carbon-free energy future. Finally, I will review the state-of-the-art, highlight the grand challenges/impact, and overview the proposed research program to tackle this problem in my future group.
Dr. Ke Sun is currently a senior postdoctoral fellow advised by Professor Nathan Lewis in the Division of Chemistry and Chemical Engineering and the Joint Center for Artificial Photosynthesis (JCAP) at Cal Tech. His research during the past 3 years in solar fuel from only water and air pursues the development of solutions to fill the knowledge gap in realizing an efficient and stable solar-to-fuel conversion through a rational management of photons, electrons and ions in the coupled photo-electro-chemical process. To advance the nanoscale characterization and develop understandings of the corrosion/passivation/degradation process on photoelectrodes while in-action, he has recently begun to develop platforms to integrate state-of-the-art microscopic/spectroscopic techniques with in-situ electrochemical measurement. He obtained his Ph.D degree from the University of California, San Diego in 2013 in Prof. Deli Wang’s group at the Department of Electrical and Computer Engineering. His graduate work involved the synthesis and integration of quantum confined nanostructures of III-V compound materials, silicon, metal and dielectrics using chemical vapor deposition, metal organic vapor deposition, molecular beam epitaxy, dry etching, patterned electrodeposition, and hydrothermal growth, and their applications in biosensors, artificial retina, photovoltaics, optoelectronics, transistors, and solar fuel devices.
Dr. Sun has published 37 publications in Chem. Rev., PNAS, JACS, Energy Env. Sci., Nano Letters, ACS Nano, and etc. A lot of his work has been featured by the U.S. Department of Energy, Nature Energy, MIT Technology Review, Discovery and etc. He has 4 ESI highly cited papers in Physics and Chemistry and has been cited for >1150 times. He has presented 11 invited talks in conferences and 12 invited seminars at universities and companies. He also holds 2 patents and several university disclosures.
MSE Colloquium: Keivan Stassun, The Fisk-Vanderbilt Masters-to-PhD Bridge Program: A Model for Dramatically Increasing Diversity at the PhD Level in Science and Engineering
We briefly review the current status of underrepresented minorities in science and engineering: The underrepresentation of Black-, Hispanic-, and Native-Americans is an order of magnitude problem. We then describe the Fisk-Vanderbilt Masters-to-PhD Bridge program as a successful model for addressing this problem. Since 2004 the program has admitted nearly 120 students, 90% of them underrepresented minorities (50% female), with a retention rate of 90%. Already, the program is the top producer of African American master’s degrees in physics, and is the top producer of minority PhDs in astronomy, materials science, and physics. We summarize the main features of the program including its core strategies: (1) replacing the GRE in admissions with indicators that are better predictive of long-term success, (2) partnering with a minority-serving institution for student training through collaborative research, and (3) using the master’s degree as a deliberate stepping stone to the PhD. We show how misuse of the GRE in graduate admissions may by itself in large part explain the ongoing underrepresentation of minorities in PhD programs, and we describe our alternate methods to identify talented individuals most likely to succeed. We describe our mentoring model and toolkit which may be utilized to enhance the success of all PhD students.
After earning A.B. degrees in physics and in astronomy from the University of California at Berkeley, and the Ph.D. in astronomy from the University of Wisconsin—Madison, Stassun was a NASA Hubble postdoctoral fellow before joining the Vanderbilt faculty in 2003. A recipient of a CAREER award from NSF and a Cottrell Scholar Award from the Research Corporation, Stassun’s research on the birth of stars and planetary systems has appeared in more than 200 peer-reviewed journal articles. He is co-investigator on the NASA Transiting Exoplanet Survey Satellite (TESS) mission and chairs the executive committee of the Sloan Digital Sky Survey. From 2004 to 2015, he served as founding director of the Fisk-Vanderbilt Masters-to-PhD Bridge Program, through which Fisk has become the top producer of African American master’s degrees in physics and Vanderbilt has become the top producer of PhDs to underrepresented minorities in physics, astronomy, and materials science. He has served on the NSF Committee for Equal Opportunity in Science and Engineering, has been recognized by the Fletcher Foundation for “contributions advancing the spirit of Brown versus Board of Education,” is a recipient of the American Physical Society’s Nicholson Medal for Human Outreach, and is a Fellow of the American Association for the Advancement of Science. In 2010, Stassun was invited to give expert testimony on “broadening participation in STEM” to the US House of Representatives Committee on Science and Technology. In 2016 Stassun launched a new interdisciplinary research initiative at Vanderbilt entitled Big Data Visualization and the Autistic Mind.
MSE Colloquium: David Cahill, Ultrafast Heat Transfer in Nanoscale Materials
On the macroscopic lengths scales of conventional engineering systems, heat transfer by conduction is generally a slow process well-described by the heat diffusion equation. The characteristic time-scale of diffusion scales with the square of length; therefore, at nanometer length scales, heat conduction can involve processes that occur on time-scales of picoseconds, i.e., a few trillionth of a second. We use ultrafast pump-probe optical techniques to directly study a variety of unconventional heat transfer mechanisms that are critical in nanoscale devices and nanoscale materials. Our studies encompass a diverse variety of systems (metallic nanoparticles for photothermal medical therapies, phase change materials for solid-state memory, and heat-assisted magnetic recording) and physical mechanisms (the thermal conductance of interfaces between dissimilar materials, the non-equilibrium between thermal excitations of electrons, phonons, and magnons, and the cross-terms in the transport of heat, charge, and spin). In this talk I will highlight three recent examples: i) ultrafast thermal transport in the surroundings of plasmonic nanostructures; ii) limitations on ultrafast heating of metallic multilayers imposed by electron-phonon coupling; and iii) the generation of currents of magnetization by the spin-dependent Seebeck effect and extreme heat fluxes exceeding 100 GW m-2.
is the Willett Professor and Department Head of Materials Science and Engineering at the University of Illinois at Urbana-Champaign. He joined the faculty of the U. Illinois after earning his Ph.D. in condensed matter physics from Cornell University, and working as a postdoctoral research associate at the IBM Watson Research Center. His research program focuses on developing a microscopic understanding of thermal transport at the nanoscale; the discovery of materials with enhanced thermal function; the interactions between phonons, electrons, photons, and spin; and advancing fundamental understanding of interfaces between materials and water. He received the 2015 Touloukian Award of the American Society of Mechanical Engineers and the Peter Mark Memorial Award from the American Vacuum Society (AVS); is a fellow of the AVS, American Physical Society (APS) and Materials Research Society (MRS); and a past-chair of the Division of Materials Physics of the APS. David Cahill
MSE Colloquium: Jian Luo, Understanding 2-D Interfacial Phases to Help Decipher the Materials Genome
A piece of ice melts at 0 °C, but a nanometer-thick surface layer of the ice can melt at tens of degrees below zero. This phenomenon, known as “premelting,” was first recognized by the physicist Michael Faraday. Materials scientists have discovered that the surfaces and interfaces in engineered materials can exhibit more complex phase-like behaviors at high temperatures, which can affect the fabrication and properties of a broad range of metallic alloys and ceramic materials. Specifically, recent studies of 2-D grain-boundary (GB) phases (also called “complexions”) shed light on several long-standing mysteries in materials science, including the origins and atomic-level mechanisms of activated sintering and liquid metal embrittlement. Analogous 2-D surface phases have also been studied and utilized to improve the performance of various functional ceramics for energy-related applications, including batteries, supercapacitors, photocatalysts, and oxygen-ion conductors. Since bulk phase diagrams are one of the most useful tools for materials design, it is conceived that interfacial “phase” diagrams can be developed as a useful materials science tool, in support of the Materials Genome Initiative.
If time permits, I will also briefly discuss our on-going studies on (1) understanding the mechanisms of flash sintering of ceramics, where we have developed a model to predict the onset flash temperature with a precision of £ ±6 °C and achieved, e.g., the sintering of ZnO to >97% density at an extremely low furnace temperature of < 120 °C in ~30 seconds, (2) fabricating an new class of high-entropy, ultra-high-temperature ceramics, e.g., (Hf0.2Zr0.2Ta0.2Nb0.2Ti0.2)B2 and five other metal diborides with a unique layered (quasi-2D), high-entropy, crystal structure, as well as two new groups of fluorite and perovskite high-entropy oxides, and (3) stabilizing nanocrystalline materials at high temperatures using high-entropy GBs.
Jian Luo graduated from Tsinghua University with dual Bachelor’s degrees. After receiving his Ph.D. degree in Ceramics from M.I.T. in 2001, Luo worked in the industry for more than two years with Lucent Technologies Bell Laboratories and OFS/Fitel. In 2003, he joined the Clemson faculty, where he served as an Assistant/Associate/Full Professor of Materials Science and Engineering. In 2013, he moved to UCSD as a Professor of NanoEngineering and Professor of Materials Science and Engineering. He received a National Science Foundation CAREER award in 2005 (from the Ceramics program) and an Air Force Office of Scientific Research Young Investigator award in 2007 (from the Metallic Materials program). Luo was named as a National Security Science and Engineering (Vannevar Bush) Faculty Fellow by the U.S. Department of Defense in 2014 and elected as a Fellow of the American Ceramic Society in 2016.
WE-MSE Joint Colloquium: Sam Sham, Down-selection and Code Qualification of Advanced Structural Material for High Temperature Reactor Applications
This talk is a joint WE-MSE Colloquium presentation.
Please note the time and location (9:30 a.m., rm 111 EJTC) as this talk wil be held outside of the scheduled MSE/WE 7895 timeframe.
The mission of the Office of Nuclear Energy (NE) of the Department of Energy is to advance nuclear power to meet the nation’s energy, environmental, and energy security needs. A variety of research and development activities in the advanced materials areas is being supported by NE to significantly improve the efficiency, safety, performance, and economics of advanced high temperature reactor systems. In addition to the operating temperature range, the selection of construction materials for an advanced reactor is critically dependent on the coolant system because of material compatibility and mass transfer issues, particularly for the lengthy design lifetime desired to reduce the annualized capital cost.
In this presentation, an overview of a multi-Laboratory effort in the down-selection of an advanced austenitic alloy for structural applications in high temperature reactor systems will be given. The requirements and challenges for the Code qualification of this advanced alloy in the nuclear section of the ASME Code in support of the design, construction and licensing of advanced high temperature reactors are discussed.
Nuclear energy is always on, produces zero carbon emission, and contributes to energy diversity. Nuclear can be part of the energy mix that provides economic and environmental benefits for the United States.
We encourage the best and the brightest graduates to join us to address these materials challenges.
Dr. Sham is the Technology Director in the Nuclear Engineering Division at Argonne National Laboratory. His technical specialty is in deformation and failure of advanced materials and structural mechanics technologies for high temperature reactors. He is Technology Area Lead for the multi-Laboratory advanced materials R&D activities of the Office of Advanced Reactor Technologies, DOE-NE. The portfolio includes advanced alloys, graphite, and SiC/SiC composites for structural applications in high temperature thermal and fast spectrum reactors. In addition, he leads the DOE-NE international R&D efforts on advanced materials and code qualification for sodium-cooled fast reactor structural applications. He is a member of the ASME Boiler and Pressure Vessel (BPV) Committee on Construction of Nuclear Facility Components (III), and BPV III Executive Committee. He chairs BPV III Subgroup on Elevated Temperature Design, which is responsible for the development and maintenance of design rules for nuclear components in elevated temperature service. He was elected ASME Fellow in 2000.
Before he joined Argonne in 2015, Dr. Sham was a Distinguished R&D Staff Member at Oak Ridge National Laboratory, held senior positions with AREVA NP Inc. and Knolls Atomic Power Laboratory, and was tenured faculty at Rensselaer Polytechnic Institute. He holds a B.Sc. degree, First Class Honour, in Mechanical Engineering from the University of Glasgow, Scotland, and M.S. and Ph.D. degrees (Mechanics of Solids and Structures) as well as an M.S. (Applied Mathematics) from Brown University.
MSE Colloquium: Muge Acik, Surfaces and Interfaces of Nanostructured Materials for Energy Efficient Processing
As an alternative to silicon technology, graphene (nanoelectrode) thin films are fabricated for flexible nanoelectronics and energy storage (ultracapacitors and batteries), and with perovskite thin films (light harvester) for low-cost and energy-efficient photovoltaics. However, modulation of imperfections such as intrinsic defects at the surfaces and interfaces of graphene thin films derived from graphene oxide is a standing challenge. Indeed, uncontrolled chemistry and non-stoichiometry hinge strongly on the quality of graphene-derived thin films in contact with perovskites. Most importantly, the performance and lifetime of perovskite photovoltaics are strongly affected by interfacial chemical modification with high temperature processing and phase transitions during the perovskite growth. Implementation of organic-inorganic graphene nanomaterials in photovoltaics is therefore significant due to controllable band gap through functionalization and n/p doping, high electron mobility and easy solution processability to enhance charge transport efficiency by controlling electron/hole recombination.
In this seminar, I will first introduce how we monitor edge and basal plane oxygen interactions in graphene-derived thin films during thermal reduction of graphene oxide, and at the graphene/perovskite interfaces during the growth of methylammonium lead halide perovskites by in situ spectroscopy to understand defect mechanisms. Next, I will focus on the impact of etch hole formation in the presence of trapped water at the interlayers of reduced graphene oxide at 125°C-350°C. Then, I will present the first experimental demonstration of an unusual infrared band at the edge defects of graphene at 850°C, and discuss edge oxygen termination in graphene at the nanoscale for photovoltaics. Later, I will introduce a new in situ growth method of methylammonium lead halide perovskites as a substrate- and annealing- free approach following a nucleophilic substitution mechanism to address device stability issues. In the light of current fundamental findings, finally, I will review my future research plans for light and energy harvesting hybrid systems with motivation of discovering new materials and processes to improve reliability for wearable nanoelectronics as solar textiles, and for energy and health care.
Muge Acik is currently an Argonne Scholar-Named Postdoctoral Fellow at Argonne National Laboratory. She obtained a B.S. in chemistry from Izmir Institute of Technology (Turkey), a M.S. in materials science and nanoengineering from Sabanci University (Turkey), and a Ph.D. in materials science and engineering from the University of Texas at Dallas. She also worked for Texas Instruments Inc. as a Technology Transfer Process and a Failure Analysis Engineer, and performed process transfer, failure-defect analysis and thin film characterization for memory device production. Her PhD studies and current research at Argonne focus on fundamental studies with graphene-derived nanomaterials for nanoelectronics, energy storage, and perovskite growth studies for photovoltaics. Dr. Acik has authored more than 24 SCI-index journal publications that are cited more than 2000 times. She is a member of the professional societies of MRS, AVS, and ACS, and the recipient of 2015 Distinguished Joseph Katz Postdoctoral Fellowship, 2011 MRS Graduate Student Silver Award, and 2011 MRS Best Poster Award.
Affiliation: School of Electrical, Computer, and Energy Engineering, Arizona State University
Title: Across Dimensions and Scales: Correlative Imaging and Data Analytics to Design Next-Generation Solar Absorbers
Integrating and synthesizing correlative information is something our brain performs seamlessly every second of the day from information gathered by our senses from our “operating” environment. In the field of energy conversion technology the confluence of state-of-the-art characterization approaches and advanced computing will enable us to emulate this highly efficient process at unimaginable speeds, thus allowing us to design next generation materials and devices.
High conversion efficiency and long device lifetimes requires exercising nanoscale control over the material’s microstructure and composition as well as transport across device interfaces throughout multiple length scales. For decades we have focused on pushing technique’s resolution close to the physical limits, almost to the point where it has become commoditized. While high resolution is necessary to develop emerging energy materials, multimodality sensing and functionality are univocally more valuable. This presentation will cover recent results in the polycrystalline CuInGaSe2 system and show that the key lies in the multimodal evaluation of the device under operating conditions and the kinetics that govern compositional inhomogeneities.
Professor Bertoni received her PhD from Northwestern University in 2007 in Materials Science and Engineering with a minor in Chemistry. She joined ASU as an Assistant Professor in 2012. Prior to this, she held senior scientist positions at two emerging start-up firms in the photovoltaic industry and a visiting scientist appointment at the Massachusetts Institute of Technology (2010-2012). Her previous postgraduate experience includes a postdoctoral appointment at the Massachusetts Institute of Technology (2008-2010), a Marie Curie postdoctoral fellowship at Creavis Technologies & Innovation in Germany (2007-2008) and a visiting researcher appointment at the National Renewable Energy Laboratory. She has published over 60 research articles in peer-reviewed journals, and presented more than 120 papers at scientific meetings. She has received multiple awards and recognitions, including most recently selection to the National Academy of Engineering 2017 US Frontiers of Engineering and ASU’s 2016 Outstanding Assistant Professor. She currently serves at the Advanced Photon Source MBA upgrade user board and is active in various committees and chairing positions at the IEEE photovoltaic specialists conferences.