APEX Team

APEX consists of a team of interdisciplinary scientists.

Led by NREL, APEX also includes researchers from Argonne National Laboratory, Colorado School of Mines, Johns Hopkins University, Kyma Technologies, Morgan State University, and the University of Virginia.

Directors

Nancy Haegel, APEX director, NREL
Nancy Haegel is a materials scientist with interests in semiconductor materials and devices. She serves as the director of APEX. She has worked on the basic science of semiconductor materials for infrared detectors, photovoltaics, and optoelectronics devices, using advanced imaging techniques.

Michael Spencer, APEX deputy director, Morgan State University
Mike Spencer has decades of expertise in power electronics devices and wide bandgap materials. He serves as the deputy director for APEX. Spencer has led efforts leading to advances in silicon carbide, two-dimensional materials, and new materials for power electronics.

Senior Investigators

Kirstin Alberi, NREL
Kirstin Alberi serves as an integrator in APEX, making connections between aims to strengthen the scientific questions and impact of the research. She brings a substantial background in semiconductor epitaxy and heterojunction formation to the team.

MVS Chandrashekhar, Morgan State University
Chandrashekhar (Chandra) leads Aim 2 and is an expert in power electronics and leading efforts at Morgan State on the growth, surface control, and characterization of ScB₂ and other new single crystal metallic ceramics. He will also lead liftoff and device thermal behavior investigations.

Patrick Hopkins, University of Virginia
Patrick Hopkins leads the ExSiTE (Experiments and Simulations in Thermal Engineering) Lab and brings expertise in the measurement of thermal properties of thin films and thermal conductance across interfaces using various optical pump-probe techniques.

Stephan Lany, NREL
Stephan Lany is the lead for Aim 1, focusing on developing and applying methods to predict interface atomic structures from first principles, which is a prerequisite for the calculation of electronic properties central to APEX. His computational work will guide experimental efforts in APEX by predicting the variation of interface properties as a function of synthesis conditions.

Jacob Leach, Kyma Technologies
Jacob Leach is an expert in hydride vapor phase epitaxy (HVPE) materials growth. In APEX, he will focus on the interface science of HVPE for the growth of high-Al-content aluminium gallium nitride (AlGaN).

Jessica McChesney, Argonne National Lab
Jessica McChesney is a beamline scientist at the Advanced Photon Source with expertise in studying the electronic properties of materials and interfaces using x-ray techniques. In APEX, she leads crosscutting correlative research in Aim 4.

Tyrel McQueen, Johns Hopkins University
Tyrel McQueen is a professor of chemistry with expertise in combining new synthetic techniques with the search for new materials functionality. In APEX, he leads collaborative efforts to utilize unique high-temperature, float zone single crystal growth capabilities to synthesize novel substrate materials for vertical power electronic devices.

John Simon, NREL
John Simon is the lead for Aim 3 and brings expertise in HVPE growth and wide bandgap materials. He will investigate conditions of AlGaN grown by HVPE, studying kinetics and interface control and understanding growth for high quality AlGaN at low temperatures to enable integration with novel substrates.

Heather Splawn, Kyma Technologies
Heather Splawn brings expertise in manufacturing ultra-wide bandgap (UWBG) materials. She will lead Kyma’s efforts in APEX for in-situ monitoring to understand AlGaN growth kinetics during HVPE.

Steven Spurgeon, NREL
Steven Spurgeon is an expert in AI-driven materials discovery and design. In APEX, Steven is leading correlative interface characterization efforts using high-resolution, data-driven characterization and materials design informed by advanced scanning transmission electron microscopy and electron energy loss spectroscopy.

Vladan Stevanovic, Colorado School of Mines
Vladan Stevanovic is a theoretical solid-state physicist with expertise in computational materials focused on inorganic functional materials. He will contribute to the interface and contact stabilization design and defect understanding in Aim 1, to be applied in Aims 2–3.

Brooks Tellekamp, NREL
Brooks Tellekamp is an expert in materials science for applications in next-generation microelectronics, including power electronics, neuromorphic computing, and electronics operating in harsh conditions. In APEX, he will study synthesis and interface science for new metallic substrate materials and UWBG materials, such as AlGaN.

Andriy Zakutayev, NREL
Andriy Zakutayev brings expertise in the fields of novel materials for energy applications, including power electronics. His efforts in APEX will focus on interface design and stabilization, especially for oxide semiconductors designed for high-temperature, high-power applications.

Postdocs, Students, and Interns

APEX also benefits from the expertise of a talented team of postdocs, graduate students, undergraduate students, and interns.