| Autor: |
Shao S; State Key Laboratory of Polymer Physics and Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences , Changchun 130022, People's Republic of China., Hu J; State Key Laboratory of Polymer Physics and Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences , Changchun 130022, People's Republic of China.; University of the Chinese Academy of Sciences , Beijing 100049, People's Republic of China., Wang X; State Key Laboratory of Polymer Physics and Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences , Changchun 130022, People's Republic of China., Wang L; State Key Laboratory of Polymer Physics and Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences , Changchun 130022, People's Republic of China., Jing X; State Key Laboratory of Polymer Physics and Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences , Changchun 130022, People's Republic of China., Wang F; State Key Laboratory of Polymer Physics and Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences , Changchun 130022, People's Republic of China. |
| Abstrakt: |
We demonstrate novel molecular design for thermally activated delayed fluorescence (TADF) polymers based on a nonconjugated polyethylene backbone with through-space charge transfer effect between pendant electron donor (D) and acceptor (A) units. Different from conventional conjugated D-A polymers with through-bond charge transfer effect, the nonconjugated architecture avoids direct conjugation between D and A units, enabling blue emission. Meanwhile, spatial π-π interaction between the physically separated D and A units results in both small singlet-triplet energy splitting (0.019 eV) and high photoluminescence quantum yield (up to 60% in film state). The resulting polymer with 5 mol % acceptor unit gives efficient blue electroluminescence with Commission Internationale de l'Eclairage coordinates of (0.176, 0.269), together with a high external quantum efficiency of 12.1% and low efficiency roll-off of 4.9% (at 1000 cd m -2 ), which represents the first example of blue TADF nonconjugated polymer. |
