Pyrazine-Based Blue Thermally Activated Delayed Fluorescence Materials: Combine Small Singlet–Triplet Splitting With Large Fluorescence Rate
Metal-free thermally activated delayed fluorescence (TADF) emitters have emerged as promising candidate materials for highly efficient and low-cost organic light-emitting diodes (OLEDs). Here, a novel acceptor 2-cyanopyrazine is selected for the construction of blue TADF molecules via computer-assis...
| Main Authors: | , , , , , , |
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| Format: | Article |
| Language: | English |
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Frontiers Media S.A.
2019-05-01
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| Series: | Frontiers in Chemistry |
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| Online Access: | https://www.frontiersin.org/article/10.3389/fchem.2019.00312/full |
| _version_ | 1819148406128377856 |
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| author | Junyuan Liu Keren Zhou Dan Wang Chao Deng Ke Duan Qi Ai Qisheng Zhang |
| author_facet | Junyuan Liu Keren Zhou Dan Wang Chao Deng Ke Duan Qi Ai Qisheng Zhang |
| author_sort | Junyuan Liu |
| collection | DOAJ |
| description | Metal-free thermally activated delayed fluorescence (TADF) emitters have emerged as promising candidate materials for highly efficient and low-cost organic light-emitting diodes (OLEDs). Here, a novel acceptor 2-cyanopyrazine is selected for the construction of blue TADF molecules via computer-assisted molecular design. Both theoretical prediction and experimental photophysical data indicate a small S1-T1 energy gap (ΔEST) and a relative large fluorescence rate (kF) in an o-phenylene-bridged 2-cyanopyrazine/3,6-di-tert-butylcarbazole compound (TCzPZCN). The kF value of 3.7 × 107 s−1 observed in a TCzPZCN doped film is among the highest in the TADF emitters with a ΔEST smaller than 0.1 eV. Blue TADF emission is observed in a TCzPZCN doped film with a short TADF lifetime of 1.9 μs. The OLEDs using TCzPZCN as emitter exhibit a maximum external quantum efficiency (EQE) of 7.6% with low-efficiency roll-off. A sky-blue device containing a derivative of TCzPZCN achieves an improved EQE maximum of 12.2% by suppressing the non-radiative decay at T1. |
| first_indexed | 2024-12-22T13:45:12Z |
| format | Article |
| id | doaj.art-ad91a154efc84d2fb02d34b501825540 |
| institution | Directory Open Access Journal |
| issn | 2296-2646 |
| language | English |
| last_indexed | 2024-12-22T13:45:12Z |
| publishDate | 2019-05-01 |
| publisher | Frontiers Media S.A. |
| record_format | Article |
| series | Frontiers in Chemistry |
| spelling | doaj.art-ad91a154efc84d2fb02d34b5018255402022-12-21T18:23:48ZengFrontiers Media S.A.Frontiers in Chemistry2296-26462019-05-01710.3389/fchem.2019.00312456712Pyrazine-Based Blue Thermally Activated Delayed Fluorescence Materials: Combine Small Singlet–Triplet Splitting With Large Fluorescence RateJunyuan LiuKeren ZhouDan WangChao DengKe DuanQi AiQisheng ZhangMetal-free thermally activated delayed fluorescence (TADF) emitters have emerged as promising candidate materials for highly efficient and low-cost organic light-emitting diodes (OLEDs). Here, a novel acceptor 2-cyanopyrazine is selected for the construction of blue TADF molecules via computer-assisted molecular design. Both theoretical prediction and experimental photophysical data indicate a small S1-T1 energy gap (ΔEST) and a relative large fluorescence rate (kF) in an o-phenylene-bridged 2-cyanopyrazine/3,6-di-tert-butylcarbazole compound (TCzPZCN). The kF value of 3.7 × 107 s−1 observed in a TCzPZCN doped film is among the highest in the TADF emitters with a ΔEST smaller than 0.1 eV. Blue TADF emission is observed in a TCzPZCN doped film with a short TADF lifetime of 1.9 μs. The OLEDs using TCzPZCN as emitter exhibit a maximum external quantum efficiency (EQE) of 7.6% with low-efficiency roll-off. A sky-blue device containing a derivative of TCzPZCN achieves an improved EQE maximum of 12.2% by suppressing the non-radiative decay at T1.https://www.frontiersin.org/article/10.3389/fchem.2019.00312/fullthermally activated delayed fluorescence (TADF)pyrazineblue organic light-emitting diodes (OLED)fluorescence rate constantsinglet-triplet splitting |
| spellingShingle | Junyuan Liu Keren Zhou Dan Wang Chao Deng Ke Duan Qi Ai Qisheng Zhang Pyrazine-Based Blue Thermally Activated Delayed Fluorescence Materials: Combine Small Singlet–Triplet Splitting With Large Fluorescence Rate Frontiers in Chemistry thermally activated delayed fluorescence (TADF) pyrazine blue organic light-emitting diodes (OLED) fluorescence rate constant singlet-triplet splitting |
| title | Pyrazine-Based Blue Thermally Activated Delayed Fluorescence Materials: Combine Small Singlet–Triplet Splitting With Large Fluorescence Rate |
| title_full | Pyrazine-Based Blue Thermally Activated Delayed Fluorescence Materials: Combine Small Singlet–Triplet Splitting With Large Fluorescence Rate |
| title_fullStr | Pyrazine-Based Blue Thermally Activated Delayed Fluorescence Materials: Combine Small Singlet–Triplet Splitting With Large Fluorescence Rate |
| title_full_unstemmed | Pyrazine-Based Blue Thermally Activated Delayed Fluorescence Materials: Combine Small Singlet–Triplet Splitting With Large Fluorescence Rate |
| title_short | Pyrazine-Based Blue Thermally Activated Delayed Fluorescence Materials: Combine Small Singlet–Triplet Splitting With Large Fluorescence Rate |
| title_sort | pyrazine based blue thermally activated delayed fluorescence materials combine small singlet triplet splitting with large fluorescence rate |
| topic | thermally activated delayed fluorescence (TADF) pyrazine blue organic light-emitting diodes (OLED) fluorescence rate constant singlet-triplet splitting |
| url | https://www.frontiersin.org/article/10.3389/fchem.2019.00312/full |
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