IN-PERSON EVENT - REGISTER HERE to attend

By Dr Rosa E. Diaz - Elmore School of Electrical and Computer Engineering at Purdue University, Indiana, USA

Abstract: Heterogeneous interfaces in quantum devices often undergo structural and chemical transformations when integrating dissimilar materials, leading to various forms of disorder that can impact their stability and performance. This talk will highlight how atomic-resolution scanning transmission electron microscopy (STEM) provides a powerful approach to identify, quantify, and characterize these interfaces at the atomic scale. We will present electron microscopy studies across different interfaces in superconductor-semiconductor systems used for quantum computation as well as nitride heterostructures used most commonly in optoelectronic devices. By leveraging high-resolution imaging, spectroscopy, and quantitative analysis, we extract critical interface characteristics such as roughness, bonding states, and chemical inhomogeneities, linking them to fabrication processes and electronic measurements. For example, in Al/semiconductor interfaces, we assess the bonding states of Al to determine the presence of metallic or oxidized species, providing insights into oxidation behavior and material stability. Through these investigations, we demonstrate how atomic-resolution electron microscopy supports a metric-driven approach to studying disorder at heterogeneous interfaces, offering useful insights into interface quality. These information can help optimize material growth and fine-tune fabrication processes, ultimately contributing to the advancement of next-generation devices.

Biography: Dr. Rosa E. Diaz is a Research Professor at the Elmore School of Electrical and Computer Engineering at Purdue University, specializing in electron microscopy and electronic device metrology. She earned her Ph.D. in Materials Science and Engineering from Arizona State University. She has held research positions at Brookhaven National Laboratory, the Okinawa Institute of Science and Technology, and Birck Nanotechnology Center at Purdue. Dr. Diaz has published over 45 research papers in semiconductors, quantum materials, catalysis, and nanotechnology collaborating across disciplines. She is an active member of the Microscopy Society of America, MRS, and AAAS, contributing to the development of cutting-edge characterization methodologies as well as STEM curriculum for K-12 education and outreach. Through her extensive partnerships with academia and industry, she is actively driving innovation in materials characterization techniques for next-generation electronic and quantum devices, ensuring fundamental research translation into technological advancements.

Hosted by Dr Sonia Ruiz Raga, CSIC Tenured Scientist at Nanostructured Materials for Photovoltaic Energy Group at ICN2.