Carbazole–pyrene derivatives for undoped organic light-emitting devices
| Autor: | Ming-Fai Lo, Chi-Chiu Ko, Shiu-Lun Lai, Tsz-Wai Ng, Chun-Sing Lee, Shuit-Tong Lee, Michael C. Y. Chan, Qing-Xiao Tong |
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| Rok vydání: | 2011 |
| Předmět: |
Organic electronics
Photoluminescence business.industry Carbazole Quantum yield General Chemistry Electroluminescence Condensed Matter Physics Photochemistry Electronic Optical and Magnetic Materials Biomaterials chemistry.chemical_compound chemistry Materials Chemistry OLED Optoelectronics Quantum efficiency Electrical and Electronic Engineering Chromaticity business |
| Zdroj: | Organic Electronics. 12:541-546 |
| ISSN: | 1566-1199 |
| Popis: | Two carbazole–pyrene derivatives, namely 3,6-dipyrenyl-9-(4′- tert -butylphenyl) carbazole (BPyC) and 3,6-dipyrenyl-9-(4′-pyrenylphenyl) carbazole (TPyC), have been designed and synthesized for application in organic light-emitting devices (OLEDs). While the two compounds have similar chemical structures and photoluminescent properties, OLEDs based on them show distinct electroluminescence (EL) spectra. The BPyC-based devices show a single peak saturated blue emission with CIE coordinates of (0.15, 0.18); whereas the TPyC-based devices exhibit two emission peaks at blue and yellow hues with CIE coordinates of (0.22, 0.29). The difference in their EL spectra is attributed to the substitution of the t -butyl unit of BPyC with a pyrenyl group to form TPyC, which effectively increases the electron-donating property and results in exciplex formation at its interface with the electron-accepting TPBI. A high external quantum efficiency of 3.11% is achieved in the TPyC-based devices. Influences of chemical structure and fluorescent quantum yield on the efficiency of exciplex emission are discussed. |
| Databáze: | OpenAIRE |
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