Fabricage van White Light-emitting elektrochemische cellen met Stable Emissie van 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
De auteurs geven een benadering voor het vervaardigen van stabiele witte lichtemissie van polymere lichtemitterende elektrochemische cellen (plecs) een actieve laag bestaande uit blauwe fluorescerende poly (9,9-di-n-dodecylfluorenyl-2,7-diyl) ( PFD) en π-geconjugeerde moleculen trifenylamine. Deze witte lichtemissie afkomstig uit exciplexes gevormd tussen PFD en aminen in elektronisch aangeslagen toestanden. Inrichting bevattende PFD, 4,4 ', 4' '- tris [2-naftyl (fenyl) amino] trifenylamine (2-TNATA), poly (ethyleenoxide) en K 2 CF 3 SO 3 toonde wit-lichtemissie met Commission Internationale de l'éclairage (CIE) coördinaten van (0,33, 0,43) en een Color Rendering Index (CRI) van Ra = 73 bij een aangelegde spanning van 3,5 V. Constante spanning metingen bleek dat de CIE coördinaten van (0,27, 0,37), Ra van 67, en de emissiekleur waargenomen onmiddellijk na het aanleggen van een spanning van 5 V waren nagenoeg onveranderd stabiel na300 sec.
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
De LEC heeft een actieve laag die hydrofobe PFD en aromatische aminen, en hydrofiele polyethyleenoxide en KCF 3 SO 3. Omdat deze materialen hebben verschillende oplosbaarheden, zorgvuldige voorbereiding van de spin bekledingsoplossing kritisch onvolledige solvatatie voorkomen. Elk eerst afzonderlijk en volledig opgelost in oplosmiddelen met voldoende oplossend vermogen dan de oplossingen worden samen gemengd om een uniform mengsel te vormen. Afweging van de exciton en exiplex uitstoot is de s…
Disclosures
The authors have nothing to disclose.
Acknowledgements
Dit werk werd gedeeltelijk ondersteund door een Grant-in-Steun voor Wetenschappelijk Onderzoek (nr 24225003). Dit werk werd financieel ondersteund door de 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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