WHAT DID THE 2012 EARLY CAREER AWARD ALLOW YOU TO DO?
A wide range of technologies rely on semiconductor devices. These applications include solar cells and thermoelectrics for clean energy. Other applications include lasers and detectors for health and environmental monitoring as well as the Light Detection and Ranging (LIDAR) that supports autonomous vehicles.
By adding metallic nanoparticles into the materials, we can turn these semiconductors into nanocomposites. These nanocomposites have very different properties, which allow these materials to be used for myriad new applications.
Previously, we made these materials by a technique called molecular beam epitaxy. It produces very high-quality materials but is quite expensive and slow.
The support of the Department of Energy (DOE) Early Career Award allowed me to try a new approach to making these nanocomposite materials. This approach was based on making the nanoparticles separately and then incorporating them. Doing so offered the promise of faster growth and more materials combinations, which could allow many new applications.
Along the way, we made discoveries about how to make these nanoparticles. These discoveries can be applied to a wide range of other materials. We also found new limitations in the approaches to growing the nanomaterials we adopted. We even learned more about the materials we had produced with the conventional approach. These materials are more promising than expected—for converting heat to electrical energy—and has resulted in more research.
Additionally, two doctoral students were trained. One of them now works in the semiconductor industry and the other works for an equipment manufacturer.
The DOE Early Career Award allowed me to perform some new experiments and even those that were ultimately unsuccessful increased our knowledge base and drove further innovations.
Joshua Zide is a professor and chair in the Department of Materials Science and Engineering at the University of Delaware and a Science and Technology of Materials, Interfaces, and Processing (AVS) fellow.
SUPPORTING THE DOE SC MISSION:
The Early Career Research Program provides financial support that is foundational to early career investigators, enabling them to define and direct independent research in areas important to DOE missions. The development of outstanding scientists and research leaders is of paramount importance to the Department of Energy Office of Science. By investing in the next generation of researchers, the Office of Science champions lifelong careers in discovery science.
For more information, please go to the Early Career Research Program.
THE 2012 PROJECT ABSTRACT:
Title: Growth and Properties of New Epitaxial Metal/Semiconductor Nanocomposites
This project aims to provide a new synthesis capability to the thin film electronic materials science community that allows for the incorporation of a variety of metal and semiconductor nanoparticles into a semiconductor matrix for use in thermoelectrics, optoelectronics, and other applications.
The new method is a two‐step process. First, a gas condensation process is used to make nanoparticles of desired material compositions with controlled morphology and size. Next, the nanoparticles are incorporated into a semiconductor matrix by a melt process called liquid phase epitaxy (LPE).
This hybrid method offers more versatility in compositional variety and morphology than is currently accessible through the standard Molecular Beam Epitaxy (MBE) method and therefore provides a greater variety of materials for discovery.
BE Tew, MR Lewis, C-Y Hsu, C Ni, and JMO Zide, "Growth of ErAs:GaAs Nanocomposite by Liquid Phase Epitaxy." Journal of Crystal Growth 518, 34 (2019). [DOI: 10.1016/j.jcrysgro.2019.04.025]
BE Tew, P Vempati, LE Clinger, CC Bomberger, NI Halaszynski, T Favaloro, JH Seol, JP Feser, A Majumdar, A Shakouri, JE Bowers, J-H Bahk, and JMO Zide, “High Thermoelectric Power Factor and ZT in TbAs:InGaAs Epitaxial Nanocomposite Material.” Advanced Electronic Materials 5, 1900015 (2019). [DOI:10.1002/aelm.201900015]
MR Lewis, BE Tew, and JMO Zide, “Formation of ErAs Nanoparticles by Pulsed Laser Ablation of Pressed Powder Targets.” Journal of Electronic Materials 48, 3370 (2019). [DOI:10.1007/s11664-018-06902-z]
Additional profiles of the Early Career Research Program award recipients can be found at the Early Career Program highlights page.
The Office of Science is the single largest supporter of basic research in the physical sciences in the United States and is working to address some of the most pressing challenges of our time. For more information, please visit the Office of Science website.