Research in the Hartland Laboratory is currently supported by the National Science Foundation through the MSN and CMI programs (CHE-2002300 and CHE-1902403), and the Department of Energy through a SBIR Phase IIb grant with Photothermal Spectroscopy Corp.
Recent projects and associated papers:
Ultrafast Spectroscopy Studies of Single Nanostructures:
We use transient absorption microscopy to study energy transport and relaxation process in single nanostuctures. Current research in this area includes studies of how the breathing modes of nanoparticles dissipate their energy into their environment, and the motion of plasmons and excitons in different types of nanostructures.
Kuai Yu, Yang Yang, Junzhong Wang, Gregory V. Hartland, Guo Ping Wang, “Nanoparticle-Fluid Interactions at Ultra-High Acoustic Vibration Frequencies Studied by Femtosecond Time- Resolved Microscopy”, ACS Nano 2021, 15, 1833-1840.
Junzhong Wang, Yang Yang, Neng Wang, Kuai Yu, Gregory V. Hartland, and Guo Ping Wang, “Long Lifetime and Coupling of Acoustic Vibrations of Gold Nanoplates on Unsupported Thin Film” J. Phys. Chem. A, 2019, 123, 10339-10346.
Localized and Propagating Surface Plasmons Polaritons in Metal Nanostructures:
The field enhancements that are associated with surface plasmons are important in a number of technologies, including molecular sensing, surface enhanced spectroscopies and plasmon enhanced photocatalysis. The efficiencies of these processes depend on the dephasing times of the plasmons, which we study using single particle spectroscopy. We are interested in both the localized surface plasmon resonances of particles and propagating surface plasmons polaritons in extended metal nanostructures, such as nanowires and nanoplates.
Kyle Aleshire, Illia M. Pavlotec, Robyn Collette, Xiang-Tian Kong, Phillip D. Rack, Shubin Zhang, David J. Masiello, Jon P. Camden, Gregory V. Hartland, and Masaru Kuno, “Far-Field Mid-Infrared Imaging and Spectroscopy of Single High Aspect Ratio Gold Nanowires”, Proc. Nat. Acad. Sci. U.S.A., 2020, 117 (5), 2288-2293.
Gary Beane, Brendan S. Brown, Tuphan Devkota and Gregory V. Hartland, “Light-like Group Velocities and Long Lifetimes for Leaky Surface Plasmon Polaritons in Noble Metal Nanostripes”, J. Phys. Chem. C, 2019, 123, 15729-15737 (2019).
New Optical Techniques for Studying Nanomaterials:
A major area of research in our lab is to develop new techniques to study nanomaterials. Recent efforts in this area include the development of super-resolution IR microscopy based on photothermal heterodyne imaging (a joint project with the Kuno group).