Spin-Selective Emission in Divalent Ytterbium-doped Nanocrystals
발표자
이재준 (한국과학기술원)
연구책임자
조힘찬 (한국과학기술원)
공동저자
이재준 (한국과학기술원), 조힘찬 (한국과학기술원)
초록
내용
Lanthanide ions exhibit unique 4f–5d transitions and highly tunable optical properties. Divalent ytterbium (Yb²⁺), in particular, offers spin-resolved emission pathways but remains difficult to stabilize in colloidal systems due to its high air sensitivity. Here, we report a ligand-engineered colloidal synthesis of CsI:Yb²⁺ nanocrystals using a hot-injection approach. The nanocrystals show dual emissions, arising from spin-allowed and spin-forbidden 5d–4f transitions, respectively. By tuning the ratio of coordinating ligands, we induce controlled lattice strain that modulates the relative intensities of the two emission pathways. Time-resolved photoluminescence reveals distinct lifetime regimes, confirming their different spin character. This work demonstrates the first strain-mediated control of spin-selective Yb²⁺ emission in colloidal nanocrystals and establishes ligand engineering as a viable strategy for tuning lanthanide photophysics.