Whether developing new materials for solar power, using new techniques to build more efficient energy systems, or imagining new applications for existing technologies, Duke researchers are at the cutting edge of energy materials. Investigations by faculty at the Pratt School of Engineering and in other Duke schools, often working with graduate and undergraduate students, have led to the development of innovative applications of energy materials. These teams aim for a range of energy-related goals, such as improving the efficiency of the current energy system and reducing the environmental impacts of energy use.
Duke is capitalizing on this depth and range of expertise by forming an Energy Materials Working Group under the leadership of David Mitzi, professor in the Department of Mechanical Engineering and Materials Science at Pratt. These efforts are connecting faculty and researchers from across Duke with investigators in nearby Research Triangle Park and from industry, national labs and government agencies, foundations, and other universities. Research teams are pooling resources and expertise to demonstrate materials solutions for cost-competitive, stable, clean and equitable energy supply.
Alternatives to silicon for solar - David Mitzi
Nearly 80 percent of today’s solar cell market utilizes silicon technology, which relies on an expensive manufacturing process involving high-quality, single-crystal materials and relatively thick cells. But Pratt professor David Mitzi thinks some alternative materials may help bring down cost and improve availability for solar energy production. Mitzi is leading a research program that pursues two classes of potential silicon alternatives: metal halides and chalcogenides. A special structural family of metal halides known as perovskites can combine organic/inorganic materials and functionality within a specific crystalline structure, thereby potentially providing enhanced functionality for solar cells and other devices. Chalcogenides are compounds based on sulfur, selenium or tellurium, and at least two examples of these compounds are already being significantly commercialized.
Learn more about Mitzi’s work on innovative materials for solar cells here.
Making organic materials work for solar - Adrienne Stiff-Roberts
Solar electricity generation has skyrocketed in the past five years, but it still accounts for less than one percent of overall power generation in the United States – in part, due to the high cost of materials for solar technologies. Duke researcher Adrienne Stiff-Roberts is leading a team investigating whether organic materials can be made durable and efficient enough to be used in place of technologies currently used to generate solar power. Her team is focused on an advanced technique known as matrix-assisted pulsed laser evaporation, or MAPLE. The technique allows multiple layers of organic materials to be placed atop one another in a solar cell, something that has proved too difficult to accomplish without MAPLE. This project has the potential to bring down the cost of making solar cells, allowing the technology to be more widely available.
Perfecting the "perfect fuel" - Nico Hotz
Hydrogen produces no greenhouse emissions; its only byproduct is water. But hydrogen’s status as "the perfect fuel" is otherwise marred by high storage costs and an inefficient production process that requires hydrocarbon sources. A team of Pratt researchers is working to address these drawbacks, however. Led by assistant professor of mechanical engineering and materials science Nico Hotz, the team is developing a process that uses solar heat generation to derive hydrogen fuel from methanol, a renewably sourced chemical that can be stored inexpensively in its liquid form. Properly implemented, this technology will allow for efficient and clean creation of hydrogen fuel for home electricity generation.
Read more about hydrogen fuel research at Duke.
Solar fuel generation via photoelectrochemical water-splitting - Jeff Glass
The sustainable harvesting of the sun’s ample energy output not only depends on our ability to capture and convert it into a useful power source such as electricity, as photovoltaic cells do, but also to efficiently store it. The development of photoelectrochemical (PEC) cells has gained a lot of attention due to their ability to directly convert solar energy into a chemical fuel where the energy is simply stored in its covalent bonds. The Nanomaterials and Thin Films Lab is developing novel nanostructures that can be used as water-oxidizing photoanodes in a PEC device and enhance the overall efficiency of the PEC water-splitting process.
Optimizing microbial metabolism for biofuels production - Mike Lynch
Microbial cultures are crucial to a wide variety of modern industrial processes, from chemicals production to manufacturing pharmaceuticals. Michael Lynch, an assistant professor in the Pratt School’s Department of Biomedical Engineering, is attempting to genetically engineer a standardized system of "dynamic metabolic control" that will optimize microbial cultures for all types of industrial and medical uses. His project holds strong promise for applications in bioenergy production, for example focusing on the conversion of feedstocks into advanced biofuels and chemicals.
Learn more about Lynch’s research program.
Developing minature methane "sniffer" - Jeff Glass
A team from Duke University is working to create a next-generation methane detector to sniff out natural gas leaks across the United States. Led by Jeffrey Glass, professor of electrical and computer engineering and Hogg Family Director of Engineering Management & Entrepreneurship, the three-year, $3 million project will design, build and commercialize a miniaturized, low-cost mass spectrometer that can serve as an efficient and sensitive methane detector. The project is supported by a grant from the Department of Energy’s Advanced Research Projects Agency-Energy, as part of the Methane Observation Networks with Innovative Technology to Obtain Reductions program focused on reducing methane emissions associated with energy production to build a more sustainable energy future.
Designing thermoelectric materials one atom at a time - Olivier Delaire
Pratt professor Olivier Delaire joins Duke's energy faculty from Oak Ridge National Laboratory, where he conducts research on thermoelectric materials. Large temperature disparities within bodies constructed from these materials can produce electricity. It's a phenomenon with a multitude of technological applications - NASA has employed thermoelectric systems in its spacecrafts for years - but we don't yet fully understand the properties and conditions that yield high performance energy conversion. Delaire's research, which now continues at Duke, probes these properties at the atomic level, attempting to discover and model successful material structures that will unlock a novel means of energy production.
Read more about Delaire’s groundbreaking work.
Modular batteries to make renewables reliable - Angel Peterchev
A standard complaint about renewable fuels relates to their reliability: There’s no solar power when the sun doesn’t shine, and wind turbines don’t work if the wind isn’t blowing. So researchers are trying to figure out how to provide cost-effective storage for renewable-generated power. One such researcher at Duke is Angel Peterchev, an assistant professor in the departments of Psychiatry and Behavioral Sciences, Electrical and Computer Engineering, and Biomedical Engineering. Peterchev and his research team are working on integrated modules consisting of solar panels and batteries, which can easily be combined to generate small- or large-scale power and storage systems. Key advantages of this approach are lower energy storage costs, and technology that can be scaled up or down to suit the needs of homes, businesses and even large power plants.
Read more about the modular solar AC battery system here.
Electrode materials for supercapacitors - Jeff Glass
Supercapacitors combine high energy density, high power density and high cyclability characterisitics to meet energy storage needs that fall between those that a battery or capacitor can meet. Such needs are prevalent in the transportation, mobile electronics and renewable energy industries, which require storage devices of such capability. The Nanomaterials and Thin Films Laboratory is studying novel working/counter electrode materials.
Read more about investigations into new electrode materials.
Cutting energy transmission losses through understanding superconductivity - Sara Haravifard
Power producers are always seeking ways to cut their losses as they transmit electricity across long distances. A Duke faculty member is investigating how superconductivity can help. Sara Haravifard, in the Department of Physics, is working to better understand how to achieve high temperature superconductivity and even room temperature superconductivity, which could have a transformative impact on energy transport.
Predicting better materials for light harvesting via electronic structure theory - Volker Blum
Harvesting sunlight for photovoltaics involves several steps, including efficiently absorbing light, generating electronic excitations in the material, splitting those excitations into electrically charged carriers (electrons and so-called “holes”), and transporting the carriers to the electrodes where they are used, ideally with minimal loss. All this activity is governed at the most basic structural level of the material, at the scale of atoms and electrons. The group of Volker Blum at Duke University develops and applies theories and simulation tools that help predict, based on the electronic structure, the suitability of given materials or materials modifications for photovoltaic applications. The team’s insights are helping guide and inform the discovery of refined and new materials for photovoltaics by experimental researchers at Duke.
Learn more about the group's work.
Understanding and improving photocatalysts for generating hydrogen as a fuel - Volker Blum
“Hydrogen from sunlight” – the direct generation of hydrogen as a fuel by shining sunlight at a photocatalyst, without any intervening electrical contacts – is a key challenge in the emerging field of “solar fuels.” The group of Pratt professor Volker Blum uses quantum mechanics to develop theories and simulate nanostructured materials for creating “hydrogen from sunlight.” The team aims to connect the dots among 1) the generation of electrons from sunlight in a nanomaterial; 2) their transport to a catalytically active site; and 3) their subsequent use to convert solvated protons into gaseous H2. Among the photocatalysts they’re studying are carbon-nitrogen based nanomaterials made and characterized by collaborators at the Max Planck Institute for Solid State Research in Stuttgart, Germany (Prof. Bettina Lotsch). Targeted atomic-scale modifications of these photocatalysts can dramatically enhance their activity. By finding out how these modifications work and predicting even better ones, Blum’s team is helping pave the way for low-cost, stable, high-efficiency materials for H2 evolution.
For more information on energy materials research at Duke, contact David Mitzi (david.mitzi@duke.edu), Pratt School of Engineering.
