Hwan-Hee Cho

Jun 19, 2024 | nature.com | Hwan-Hee Cho |Sebastian Gorgon |Giacomo Londi |Samuele Giannini |Changsoon Cho |Pratyush Ghosh | +8 more

AbstractThe development of luminescent organic radicals has resulted in materials with excellent optical properties for near-infrared emission. Applications of light generation in this range span from bioimaging to surveillance. Although the unpaired electron arrangements of radicals enable efficient radiative transitions within the doublet-spin manifold in organic light-emitting diodes, their performance is limited by non-radiative pathways introduced in electroluminescence.

May 8, 2024 | nature.com | Pratyush Ghosh |Antonios M. Alvertis |Petri Murto |Alexander J. Gillett |Shengzhi Dong |Hwan-Hee Cho | +5 more

AbstractThe coupling of excitons in π-conjugated molecules to high-frequency vibrational modes, particularly carbon–carbon stretch modes (1,000–1,600 cm−1) has been thought to be unavoidable1,2. These high-frequency modes accelerate non-radiative losses and limit the performance of light-emitting diodes, fluorescent biomarkers and photovoltaic devices.

Mar 13, 2024 | nature.com | Hwan-Hee Cho |Daniel G. Congrave |Alexander J. Gillett |Stephanie Montanaro |Junzhi Ye |Marc Etherington | +8 more

AbstractHyperfluorescence shows great promise for the next generation of commercially feasible blue organic light-emitting diodes, for which eliminating the Dexter transfer to terminal emitter triplet states is key to efficiency and stability. Current devices rely on high-gap matrices to prevent Dexter transfer, which unfortunately leads to overly complex devices from a fabrication standpoint.