Fabricação de White Light-emitting células eletroquímicas com emissão estável de Exciplexes
Summary
The authors present a method for fabricating stable white-light-emitting electrochemical cells utilizing emission from exciplexes formed between a blue-emitting fluorene polymer and aromatic amines.
Abstract
Os autores apresentam uma abordagem para a fabricação de emissão de luz branca estável a partir de células electroquímicas polímero emissor de luz (PLECS) possuindo uma camada activa que consiste de poli-azul fluorescente (9,9-di-n-dodecylfluorenyl-2,7-di-ilo) ( PFD) e moléculas trifenilamina π-conjugados. Esta emissão de luz branca origina de exciplexes formados entre PFD e aminas em estados electronicamente excitado. Um dispositivo contendo PFD, 4,4 ', 4' '- tris [2-naftilo (fenil) amino] trifenilamina (2-TNATA), poli (óxido de etileno) e K 2 CF 3 SO 3 mostrou a emissão de luz branca com Commission Internationale de l'éclairage (CIE) coordenadas (0,33, 0,43) e um índice de restituição cromática (CRI) de Ra = 73 em uma voltagem aplicada de 3,5 V. medições de tensão constante mostrou que a CIE coordenadas (0,27, 0,37), Ra de 67, e a cor da emissão observada imediatamente após a aplicação de uma tensão de 5 V eram quase inalterado e estável depois300 seg.
Introduction
Research and development of polymer light-emitting electrochemical cells (PLECs) have expanded in recent years.1-15 PLECs are similar to organic light-emitting diodes (OLEDs) in that both are surface emitting organic devices and are expected to find their way into future lighting applications. OLEDs are already on the market, but the cost is still high, one reason being that OLEDs need a complicated device structure with multiple layers. In contrast, PLECs have a very simple device structure which consists of a single active layer (emitting layer) between a pair of electrodes. This means that PLECs are suited to mass production processes such as roll-to-roll printing and coating.
A PLEC has an active layer consisting of a fluorescent π-conjugated polymer (FCP). The FCP can be electrochemically doped with a polymer electrolyte (a mixture of an ion conducting polymer and a salt). The FCP is p-doped on the anode side and n-doped on the cathode side during operation, and generates excitons which emit light between the p- and n-doped regions. Therefore, the emission color reflects the exciton emission (=fluorescence) wavelength of the FCP.
Stable white light emission is important for lighting applications, and color mixing techniques which employ two or more emitters have been widely used to achieve this.10-14 Recently, we presented a different approach for obtaining stable white light emission, using an active layer which contains blue-fluorescent poly(9,9-di-n-dodecylfluorenyl-2,7-diyl) (PFD) and π-conjugated aromatic amines15. This white light emission comes from exciplexes formed between PFD and amine molecules in excited states. Exciplex emission has a broader spectrum compared to the exciton emission from the PDF and/or amines, which gives it a color close to that of natural light. This translates to a higher color rendering index (CRI), which is preferable for lighting applications.
In this article, the authors describe the procedure used to fabricate the exciplex based LECs and show the stability of their white light emission.
Protocol
Representative Results
Discussion
A LEC tem uma camada activa contendo PFD hidrofóbico e aminas aromáticas, e óxido de polietileno hidrófilo e KCF 3 SO 3. Uma vez que estes materiais têm solubilidades muito diferentes, uma preparação cuidadosa da solução de revestimento por rotação é crítico para evitar a solvatação incompleta. Cada um deve ser primeiro dissolvido separadamente e completamente em solventes de solvatação com capacidade suficiente, então as soluções são misturadas em conjunto para formar uma mist…
Disclosures
The authors have nothing to disclose.
Acknowledgements
Este trabalho foi parcialmente financiado por um Grant-in-Aid para a Investigação Científica (No. 24.225.003). Este trabalho foi apoiado financeiramente pela JX Nippon Oil & Energy Corporation.
Materials
| Poly(9,9-di-n-dodecylfluorenyl-2,7-diyl) (PFD) | Aldrich | 571660 | |
| 4,4’,4’’-Tris[2-naphthyl(phenyl)amino]triphenylamine (2-TNATA) | Aldrich | 768669 | |
| 9,9-Dimethyl-N,N’-di(1-naphthyl)-N,N’-diphenyl-9H-fluorene-2,7-diamine (DMFL-NPB) | Aldrich | ||
| Poly(ethylene oxide) (PEO) | Aldrich | 182028 | |
| Potassium tirifluoromethansulfonate (KCF3SO3) | Aldrich | 422843 | dried under vacuum at 200 °C for 2 hr prior to use |
| Chloroform | Kanto Chemical Co. | 08097-25 | dehydrated |
| Cyclohexanone | Kanto Chemical Co. | 07555-00 | |
| SCAT 20-X (detergent) | Daiichi Kogyo Seiyaku | diluted with water | |
| Acetone | Kanto Chemical Co. | 01866-25 | Electronic grage |
| 2-propanol | Kanto Chemical Co. | 32439-75 | Electronic grage |
| 13mm GD/X Disposable Filter Device PVDF Filter Media, Polypropylene Housing | Whatman | 6872-1304 | |
| UV/O3 Treating Unit | SEN Lights Co. | SSP16-110 | |
| Spectral Photo Detector | Otsuka Electronics | MCPD 9800 | |
| Voltage Current Source Monitor | ADCMT | 6241A | |
| Evaporation Mask | Tokyo Process Service Co., Ltd. | NA | The evaporation mask was wet-etched to create openings for patterned deposition of aluminum. The size of the mask is 100 mm x 100 mm x 0.2 mm-thick. |
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