Triplet fusion upconversion using sterically protected 9,10-diphenylanthracene as the emitter

Improving the efficiency of triplet fusion upconversion (TF-UC) in the solid-state is still challenging due to the aggregation and phase separation of chromophores. In this work, two 9,10-diphenylanthracene (DPA) derivatives based on the modification of the 9,10-phenyl rings with bulky isopropyl gro...

Full description

Saved in:
Bibliographic Details
Published in:Physical chemistry chemical physics : PCCP 2020-03, Vol.22 (11), p.63-637
Main Authors: Gao, Can, Zhang, Bolong, Hall, Christopher R, Li, Li, Chen, Yeqin, Zeng, Yi, Smith, Trevor A, Wong, Wallace W. H
Format: Article
Language:English
Subjects:
Chromophores
Crystals
Emitters
Microcrystals
Phase separation
Platinum
Polyurethane resins
Polyvinyl alcohol
Solid state
Thin films
Toluene
Ultraviolet radiation
Upconversion
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:Improving the efficiency of triplet fusion upconversion (TF-UC) in the solid-state is still challenging due to the aggregation and phase separation of chromophores. In this work, two 9,10-diphenylanthracene (DPA) derivatives based on the modification of the 9,10-phenyl rings with bulky isopropyl groups (bDPA-1 and bDPA-2) were used as emitters. By using platinum octaethylporphyrin (PtOEP) as the sensitizer, TF-UC performance was comprehensively investigated in 3 media: toluene solution, polyurethane thin film and nano/micro-crystals in a polyvinyl alcohol matrix. Only a small difference in upconversion efficiency between the bulky DPAs and the DPA reference was observed in toluene solution and polyurethane thin film. However, a large improvement of TF-UC quantum yield was achieved in bDPA-2/PtOEP crystals ( Φ UC = (0.92 ± 0.05)%) with a low excitation intensity threshold (52 mW cm −2 ) compared to that of DPA/PtOEP crystals ( Φ UC = (0.09 ± 0.03)%). This difference was largely attributed to improved dispersibility of the PtOEP sensitizer in the bDPA-2 emitter crystals. The bulky DPAs also show excellent stability under UV irradiation with exposure to oxygen compared to DPA. These results provide a strategy for developing efficient solid-state TF-UC systems based on nano/micro-particles of emitter-sensitizer mixtures. Sterically protection of emitter molecules enabled improved triplet fusion upconversion performance as well as greater stability in air.
ISSN:1463-9076
1463-9084
DOI:10.1039/c9cp06311k