Events Calendar

AME - Department Seminar

Speaker: Yongjie Hu, Battelle/MIT Postdoctoral Fellow in the Department of Mechanical Engineering at the Massachusetts Institute of Technology

Talk Title: NanoEngineering for High Performance Devices and High Efficient Energy Systems

Abstract: In our everyday devices, about 60% of the primary energy is lost when converted from one form to another during operation. Nanotechnology holds the promise of dramatically improving device performance and energy efficiency. In this talk, I will discuss our efforts in engineering fundamental energy carriers at the nanoscale, in particular, for solid-state energy conversion, high-performance electronics and coherent quantum computation. First, I will present our recently developed hybrid nanostructures engineered to characterize nanoscale thermal transport. I will discuss how we can independently control the heat flow in a rationally designed path and selectively detect the local temperature. Coupling the system with ultrafast optical spectroscopy and modeling, we determined the mean free path dependent thermal conductivity in different materials. Our approach can serve as generic metrology for high throughput screening of energy materials and as a guidance tool for next-generation energy device design through phonon engineering. Second, I will present a novel material system achieved through bottom-up chemical synthesis and band structure engineering design. I will discuss our work in building high-performance electronics and integrated circuits, where the developed transistors outperformed the state-of-the-art MOSFETs and can also be applied for nano-bio interfaces. I will then talk about our development of a highly sensitive charge sensor integrated with coupled quantum dots, and show that we demonstrated full control and detection over charge dynamics, inter-coupling and lifetimes with GHz pulse manipulations. Finally, I will show that we developed the first long coherent Quantum Bit in Group-IV materials, which encodes information in the smallest energy quanta – spin, for next generation of efficient computation. We believe our efforts in developing new functional nanomaterials and structures will lead to advanced energy-conversion and device-operation paradigm in the future.

Biography: Yongjie Hu is currently the Battelle/MIT Postdoc Fellow in the Mechanical Engineering Department of the Massachusetts Institute of Technology with Professors Gang Chen and Mildred Dresselhaus, focusing on material optimization and device design for thermal transport and solar energy conversion. He obtained his M.A. (2006) and Ph.D. (2010) from Harvard University with a research focus in the areas of nanotechnology, including nanomaterials synthesis, structure characterization, high-performance devices and transport physics under the supervision of Professor Charles M. Lieber. Dr. Hu is a recipient of Micro & Nano: Heat Transfer Division Award from ASME (2012), Battelle/MIT Fellowship from MIT (2012), China’s National Award for Outstanding Students Studying Abroad (2011) and Fieser Fellowship from Harvard University (2004, 2005).

Host: Professor Spedding

Location: Hedco Neurosciences Building (HNB) - Room 100

Audiences: Everyone Is Invited

Contact: Kristi Villegas