报告题目：Van der Waals Heterostructures, High-Order Superlattices, and Extended Thin Films
The heterogeneous integration of dissimilar materials is a long pursuit of material science community. vdW integration, offers a bond-free material integration strategy to produce artificial heterostructures beyond lattice matching requirements. In this seminar, I start with a brief introduction the fundamental forces involved in vdW integration. Next, I will highlight our recent advancements in exploiting this approach for creating pinning-free metal/semiconductor junctions or photodiode approaching the Schottky-Mott limit or the intrinsic excitonic photophyiscs limit. Beyond simple heterostructures, I will discuss a broad family of vdW superlattices consisting of alternating 2D atomic layers and self-assembled molecular layers, with tailored structural symmetry, electronic band modulation and interlayer coupling as an artificial material platform for exploring emergent electronic, photonic, and exotic quantum phenomena; and introduce a unique design of vdW thin films that feature broad-area pinning-free vdW interfaces among the staggered nanosheets to ensure excellent electronic performance, and a sliding and rotation degree freedom to endow extraordinary mechanical stretchability. I will conclude with a brief perspective on exploring such artificial materials to unlock new physical limits and enable new device concepts beyond the reach of the existing materials.
Dr. Duan received his B.S. Degree from University of Science and Technology of China in 1997, and Ph.D. degree from Harvard University in 2002. He was a Founding Scientist and then Manager of Advanced Technology at Nanosys Inc. Dr. Duan joined UCLA with a Howard Reiss Career Development Chair in 2008, and was promoted to Associate Professor in 2012 and Full Professor in 2013. Dr. Duan’s research interest includes nanoscale materials, devices and their applications in future electronic and energy technologies. Dr. Duan has published over 300 papers with over 85,000 citations, and holds >50 issued US patents. He is currently an elected Fellow of Royal Society of Chemistry and Fellow of AAAS.