Non-plasmonic hot electrons from doped quantum dots

We study the generation of energetic hot electrons from Mn-doped semiconductor quantum dots taking advantage of recently discovered exciton-to-hot carrier upconversion process. Besides the effort to understand the fundamental photophysical processes involving hot hot electron generation and structural control of the process, we also utilize the energetic hot electrons for more efficient photocatalytic reactions and for driving very long-range electron transfer processes. Static and time-resolved spectroscopy, electron microscopy and photoemission current measurements are the main experimental tools for this research.

 

Photophysical properties of low-dimensional Materials

Various photophysical properties of colloidal 0D-2D semiconductor nanocrystals and metallic nanocrystals are investigated. The materials of our interest are II-VI quantum dots, metallic nanocrystals, colloidal 2D-layered transition metal dichalcogenide nanocrystals and perovskite nanocrystals. We are interested in understanding how the structure, dimensionality and interfacial structure of these nanocrystals dictate their optical, electronic and transport properties. We utilize ensemble and single-particle spectroscopy, electron and scanning probe microscopy and (photo)electrochemical methods for this research.   

 

Charge transfer/energy transfer dynamics and light induced magnetic properties in colloidal nanocrystals

We study the dynamics of energy transfer and charge transfer processes in various colloidal nanocrystals including quantum dot, magnetically doped quantum dots and hybrid structures between semiconducting and metallic nanostructures. We also study light-induced magnetic properties in magnetic nanocrystals and plasmonic nanocrystals. Main experimental tools for this research are time-resolved (pump-probe) absorption, Faraday rotation, and emission spectroscopy.
 

 

Synthesis of nanocrystals with fine structural control

We are also interested in developing the methods to syntheize various colloidal nanocrystals with controlled chemical structure and anisotropic morphology. These includes doped quantum dots, perovskite nanocrystals, 2D semiconductor nanoparticles and the heterostructures composed of these. We are intereted in the application of these materials for photonics, energy storage and photocatalysis applications.