P. James Schuck

Associate Professor
Department of Mechanical Engineering
Columbia University

In 2D semiconductors, quantum emitters are associated with localized strain that can be deterministically applied to create designer nano-arrays of single photon sources. However, the local interplay between strain, defects, and crystal structure is unclear, and the origin of the emitter states is thus unknown. In the first part of my talk, I will discuss how we combine room-temperature nano-optical imaging of excitons in strained, low-defect-density WSe2 nanobubbles with atomistic theory. Our results provide one-of-a-kind experimental and theoretical insight of how strain-induced confinement—without crystalline defects—can efficiently localize excitons on length scales commensurate with exciton size, providing key nanoscale insight into the origin of quantum emitters in monolayer WSe2.
I will then describe our work developing novel lanthanide-based upconverting nanoparticle (UCNP) designs, and applying them to new technologies. UCNPs overcome problems of photostability and continuous emission inherent in fluorescent molecules and quantum dots, but their brightness has been limited by a number of factors.  I will discuss our novel design paradigms that have resulted in UCNPs that are many orders of magnitude brighter than canonical compositions, and show how we used them to create continuous-wave (CW) upconverting microlasers smaller than red blood cells and the first-ever CW room-temperature plasmonic nanolasers. Finally, I will present our recently-discovered avalanching nanoparticles (ANPs), which show extremely nonlinear behavior (emission scales as ~I25) and enable simple confocal imaging with ~80nm resolution.

Short Bio:
Jim Schuck is an Associate Professor of Mechanical Engineering at Columbia University.  He earned his B.A. in Physics at UC Berkeley and his Ph.D. in Applied Physics at Yale University.  Jim then did his postdoctoral studies with Prof. W. E. Moerner at Stanford University, studying optical nanoantennas and single-molecule spectroscopy.  His group aims to characterize, understand and control nanoscale light-matter interactions, with a primary focus on sensing, engineering and exploiting novel optoelectronic phenomena emerging from nanostructures and interfaces.  Current research interests include the investigation and applications of 2D materials and upconverting nanoparticles (UCNPs).