Related Experiment Video
Updated: Mar 18, 2026

Integrating a Triplet-triplet Annihilation Up-conversion System to Enhance Dye-sensitized Solar Cell Response to Sub-bandgap Light
Published on: September 12, 2014
Near-Infrared-to-Visible Photon Upconversion Sensitized by a Metal Complex with Spin-Forbidden yet Strong S0-T1
Shogo Amemori1, Yoichi Sasaki1, Nobuhiro Yanai1,2
1Department of Chemistry and Biochemistry, Graduate School of Engineering, Center for Molecular Systems, Kyushu University , 744 Moto-oka, Nishi-ku, Fukuoka 819-0395, Japan.
Abstract:
Near-infrared (NIR)-to-visible (vis) photon upconversion (UC) is useful for various applications; however, it remains challenging in triplet-triplet annihilation-based UC, mainly due to the energy loss during the S1-to-T1 intersystem crossing (ISC) of molecular sensitizers. In this work, we circumvent this energy loss by employing a sensitizer with direct S0-to-T1 absorption in the NIR region. A mixed solution of an osmium complex having a strong S0-T1 absorption and rubrene emitter upconverts NIR light (λ = 938 nm) to visible light (λ = 570 nm). Sensitizer-doped emitter nanoparticles are prepared by re-precipitation and dispersed into an oxygen-barrier polymer. The obtained composite film shows a stable NIR-to-vis UC emission based on triplet energy migration (TEM), even in air. A high UC quantum yield of 3.1% is observed for this TEM-UC system, expanding the scope of molecular sensitizers for NIR-to-vis UC.
More Related Videos
11:20An Integrated System to Remotely Trigger Intracellular Signal Transduction by Upconversion Nanoparticle-mediated Kinase Photoactivation
Published on: August 30, 2017
10:42Infrared Degenerate Four-wave Mixing with Upconversion Detection for Quantitative Gas Sensing
Published on: March 22, 2019
Related Concept Videos
UV–Vis Spectroscopy: Molecular Electronic Transitions
Colors and Magnetism
When atoms or molecules absorb light at the proper frequency, their electrons are excited to higher-energy orbitals. For many main group atoms and molecules, the absorbed photons are in the ultraviolet range of the electromagnetic spectrum, which cannot be detected by the human eye. For coordination compounds, the energy difference between the d orbitals often allows photons in the visible range to be absorbed and emitted, which is seen as colors by the human...
UV–Vis Spectroscopy of Conjugated Systems
One of the factors influencing λmax is the extent of conjugation in...
Molecular Spectroscopy: Absorption and Emission
Photoluminescence: Fluorescence and Phosphorescence
A pair of electrons in a...
Ultraviolet and Visible (UV–Vis) Spectroscopy: Overview