Date: Thursday, August 22, 2024

Time:  12:00 PM - 1:00 PM MST

Location: PAIS, Room 2540

Speaker:

Dr. Terefe Habteyes

UNM Chemistry Department and Chemical Biology

Abstract：

Size-dependent optical properties of semiconductors and metals have significant technological applications, including in display devices, optical imaging, photocatalysis, and light-matter interactions. The Habteyes group utilizes the localization and enhancement of the electromagnetic field in nanoscale volumes for optical imaging beyond the diffraction limit of light, achieving spatial resolutions on the order of 10 nm, regardless of the wavelength of the excitation electromagnetic radiation, as well as for enhancing light-matter interactions. These principles will be illustrated using recent results. Infrared nano-imaging has been used to resolve chemical heterogeneity in various systems, including high-aspect-ratio nanowires formed through the self-assembly of carbon dots and solid films of citrate-capped colloidal gold nanoparticles and polymer blends. Molecular optomechanics theory is used to explain our recent observation of laser-plasmon detuning-dependent surface-enhanced Raman scattering signals. Time permitting, the possibility of selectively breaking chemical bonds using plasmon-enhanced resonant electronic excitation of molecular adsorbates will be discussed.

Biography:

Dr. Habteyes earned his B.S. and M.S. degrees in Chemistry from Addis Ababa University in 1997 and 2000, respectively. He later completed his Ph.D. in Chemistry at the University of Arizona in 2008, under the guidance of Prof. Andrei Sanov. Following his doctoral studies, he served as a postdoctoral fellow at both the University of California, Berkeley, and Lawrence Berkeley National Laboratory from 2008 to 2012, collaborating with Prof. Stephen Leone and Prof. Paul Alivisatos. In August 2012, he began his position as an assistant professor at the University of New Mexico and was promoted to associate professor with tenure in July 2018, and to full professor in July 2023. His research interests include scanning probe near-field microscopy, nanooptics, plasmonics, nanophotonics, light-matter interaction in weak and strong coupling regimes, interface properties, surface-enhanced spectroscopy, and photocatalysis.