Research
Our research aims to understand the photophysical mechanisms of how energy and charge flow in molecular, materials, and biological systems, which largely govern their function. To answer these questions, we use an interdisciplinary approach combining tools from optics, spectroscopy, materials science, and biochemistry. Below is a brief overview of our research directions. If you are interested in more details, please contact Minjung and she will be happy to discuss!
Ultrafast spectroscopy, microscopy, technique development
We utilize ultrafast transient absorption and multidimensional electronic spectroscopy, which can map photophysical processes with high temporal and spectral resolution. To be able to map dynamics across the broad range over which many materials absorb, we employ broadband light sources combined with high-speed, high-sensitivity detection. We also develop ultrafast microscopy that can spatially resolve these dynamics, because many materials are heterogeneous and the photophysics — and function — are dependent on local morphologies and structures.
M. Son et al., Opt. Express, 25, 18950−18962 (2017).
M. Son et al., Trends Chem., 3, 733−746 (2021).
Engineering photophysics using light-matter interaction
The electronic structure, and in turn, the resultant photophysical pathways in molecular, biological, and materials systems are complex and hard to systematically modulate. We employ an exciting new platform called polaritons to achieve control over these otherwise-hard-to-control parameters. Polaritons are hybrid states between light and matter, the coupling between which gives rise to a range of unique phenomena and is systematically controllable. We measure the impact of light-matter coupling and photophysics enabled by polaritons using ultrafast spectroscopy and microscopy.
M. Son et al., Nat. Commun., 13, 7305 (2022).
Tailored materials, interfaces, and their photophysics
Nanomaterials serve as building blocks for many modern devices due to their powerful electrical, mechanical, and optical properties. Ideal devices would be designed by drawing the exceptional nanoscale properties from individual building blocks and achieving their cooperative enhancement on a macroscopic scale. However, studies of material properties and photophysics so far have been largely limited due to poorly-controlled and heterogeneous structures. We develop spatially tailored molecular and materials arrays — and their interfaces — using state-of-the-art materials science tools and uncover the emergent photophysics with ultrafast spectroscopy and microscopy.
