RESEARCH INTERESTS

  • NANOPHOTONICS
    QDs can modulate the wavelength and intensity of emitted light, so they have possible application as switch probes for cellular and whole-body imaging, as optical modulators, and as light-emitting diodes. We synthesize various types of NPs, including core/shell QDs, nanorods, nanotetrapods and nanoporous materials. We have achieved photomodulation of QD conjugate by additional UV excitations that induce the electron transfers to QDs and quench their photoluminescence. We have also used inorganic capping-ligand QDs to sensitize solar cells.
  • NANOCLUSTERS
    Magic-sized clusters (MSCs) can be isolated as intermediates in quantum dot (QD) synthesis, and they provide pivotal clues in understanding QD growth mechanisms. Mechanistic studies on QDs often identify magic-sized clusters (MSCs) as intermediates between molecular precursors and final QDs MSCs are distinguished from a small size of nanoparticles (NPs), because MSCs are thermodynamically more stable than expected ones in similar size NPs. A colloidal semiconductor MSC usually consists typically less than hundreds of atoms with characteristic absorption features at fixed wavelengths.
  • NANOBIOTECHNOLOGY
    QDs present a possible new technology for in vivo bio-imaging and future medical imaging applications. QDs have proven potential as imaging contrast agents due to their bright luminescence, their resistance to photobleaching, and their tunable emission wavelengths. We developed NIR-II-emitting QD probes, and have achieved cancer diagnosis by using QD-Antibody conjugates. Also, we showed QDs in an amphiphilic polyethyleneimine derivative platform for cell labeling, targeting, gene delivery, and ratiometric oxygen sensing.
  • NANOPLASMONICS
    Metals can display Surface Plasmon Resonance (SPR) when their sizes are reduced to the nanoscale. The applications of noble metal NPs can be very diverse such as spectroscopic and imaging tools, because SPR properties can be tailored by choosing metals with appropriate dielectric properties, and by selecting the size, shape, local environment of nanoscale metallic structures. We proposed novel metal NP complexes that could be used for highly-efficient cancer therapy and for photoacoustic-guided drug delivery.

PUBLICATIONS

Accounts of Materials Research 2024 5, 9, 1097
"Silver Sulfide Nanocrystals and Their Photodetector Applications“
Jisu Kwon, Yoonbin Shin, Yunmo Sung, Hyunmi Doh, Sungjee Kim*
J. Phys. Chem. C 2024 128, 4, 1809
"Multiple Roles of Magic-Sized Clusters in Quantum Dot Synthesis“
Eunjae Lee, Yongju Kwon, Anastasia Agnes, Youngjae Ryu, and Sungjee Kim*
Chem. Mater. 2022 34, 22, 9945-9954
"Ion-Pair Ligand-Assisted Surface Stoichiometry Control of Ag2S Nanocrystals“
Yunmo Sung, Wonseok Lee, Eunjae Lee, Young Ho Ko, and Sungjee Kim*
Chemistry of Materials 2020, 32, 6864-6874
"Colloidal Synthesis of Shape-Controlled Cs2NaBiX6 (X = Cl, Br) Double Perovskite Nanocrystals: Discrete Optical Transition by Non-Bonding Characters and Energy Transfer to Mn Dopants“
Wonseok Lee‡, Doowon Choi‡, and Sungjee Kim* (W.L. and D.C. contributed equally to this work.)
Nature Communications 2020, 11, 3127
"Evolution from unimolecular to colloidal-quantum-dot-like character in chlorine or zinc incorporated InP magic size clusters“
Yongju Kwon‡, Juwon Oh‡, Eunjae Lee, Sang Hyeon Lee, Anastasia Agnes, Gyuhyun Bang, Jeongmin Kim, Dongho Kim* & Sungjee Kim* (Y.K. and J.O. contributed equally to this work.)