Applied Physics Seminar
Atomically-thin crystals derived from new classes of layered materials have rapidly emerged to enable two-dimensional (2D) nanostructures with unusual electronic, optical, mechanical, and thermal properties. While graphene has been the forerunner and hallmark of 2D crystals, newly emerged compound and single-element 2D semiconductors offer intriguing attributes beyond graphene's (e.g., including sizeable and tunable bandgaps covering a wide spectrum with technological importance). In this talk, I will describe my research group's latest efforts on investigating how mechanically active atomic-layer semiconducting nanostructures interact with optical and electronic interrogations, and on engineering such structures into ultrasensitive transducers and ultralow-power signal processing building blocks. I will show the demonstrations of highly tunable multimode resonant 2D nanoelectromechanical systems (NEMS) and vibrating-channel transistors using single-, bi- and tri-layer transition metal di-chalcogenides (TMDC), with both optical and all-electrical readout. I will describe spatially mapped mode shapes and Brownian motion detection in these atomic-layer multimode nanoresonators at room temperature, along with the device physics and coupling effects that govern the signal transduction. I shall then demonstrate black phosphorous 2D devices that exploit the crystal's unique and strong intrinsic anisotropy. I will further show strong parametric resonances and self oscillations in such 2D devices with enhanced functions and performance. Finally, I will discuss potential and initiatives toward applications including ultrasensitive detection in fundamental studies, zero-quiescent-power transducers, and 2D nanosystems integrated on meta-surfaces and/or flexible substrates for information processing.
More about the speaker: Philip Feng is currently an Assistant Professor in Electrical Engineering at Case School of Engineering, Case Western Reserve University. His group's research is primarily focused on emerging nanoscale devices and integrated systems. He received his Ph.D. from Caltech in 2007 under the supervision of Professor Michael Roukes. His recent awards include a National Science Foundation CAREER Award, 3 Best Paper Awards (with his advisees, at IEEE NEMS 2013, IEEE Int. Freq. Control Symp. 2014, and AVS Int. Symp. 2014) out of 7 nominated Finalists for Best Paper Award Competitions, and a university-wide T. Keith Glennan Fellowship. He is also the recipient of the Case School of Engineering Graduate Teaching Award (2014) and the Case School of Engineering Research Award (2015). He was one of the 81 young engineers selected to participate in the National Academy of Engineering (NAE) 2013 U.S. Frontier of Engineering (USFOE) Symposium. Subsequently, he was selected to receive the NAE Grainger Foundation Frontiers of Engineering Award in 2014. He is a senior member of IEEE, and a member of APS and AVS.