Electrochromic and electroluminescent devices based on a novel branched quasi-dendric fluorene-carbazole-2,5-bis(2-thienyl)-1H-pyrrole system
作者:Sermet Koyuncu、Ozlem Usluer、Mustafa Can、Serafettin Demic、Siddik Icli、Niyazi Serdar Sariciftci
DOI:10.1039/c0jm02366c
日期:——
We report here the synthesis of a novel branched quasi-dendric system, 9,9′-(9,9′-dihexylfluorene-2,7-diyl)bis[3,6-bis(2,5-bis(2-thienyl)pyrrol-1-yl)carbazole], (FCSNS), in four steps, followed by coating onto an ITO-coated glass surface by an electropolymerization process to give a very stable cross-linked polymeric film (poly-FCSNS). The yellowish-green color of this film in its neutral state changed reversibly to black upon oxidation. An electrochromic device, assembled in the sandwich configuration [ITO/anodically coloring polymer (poly-FCSNS)//gel electrolyte//cathodically coloring polymer/(PEDOT)/ITO], exhibited a relatively short response time (about 1 s), a high redox stability, and a high coloration efficiency (1624 cm2C−1). In addition to electrochromic studies, organic light-emitting diode (OLED) work was also carried out using FCSNS. A multilayer OLED having a configuration of ITO/PEDOT:PSS/FCSNS/Alq3/LiF : Al was fabricated, and it showed a turn-on voltage of approximately 6 V and exhibited a bright green emission with a luminance of 3700 cd m−2. The maximum luminous efficiency was found to be 2.0 cd A−1 at 14 V and 11.75 mA cm−2. The emitted light from the OLED device is green, and has the color coordinates of (x, y) (0.33, 0.54) according to CIE. Electrochemical and optical properties were also studied by using cyclic voltammetry, UV-Vis absorption and fluorescence spectroscopy, respectively.
我们在此报告了一种新型支化准树枝状体系--9,9′-(9,9′-二己基芴-2,7-二基)双[3,6-双(2,5-双(2-噻吩基)吡咯-1-基)咔唑](FCSNS)的合成过程、然后通过电聚合工艺将其涂覆在涂有 ITO 涂层的玻璃表面上,形成非常稳定的交联聚合物薄膜(聚-FCSNS)。这种薄膜在中性状态下呈黄绿色,氧化后可逆地变为黑色。以三明治结构[ITO/阳极着色聚合物(聚-FCSNS)//凝胶电解质//阴极着色聚合物/(PEDOT)/ITO]组装的电致变色装置显示出相对较短的响应时间(约 1 秒)、较高的氧化还原稳定性和较高的着色效率(1624 cm2C-1)。除了电致变色研究,还利用 FCSNS 开展了有机发光二极管(OLED)研究。制备了一种配置为 ITO/PEDOT:PSS/FCSNS/Alq3/LiF :它的开启电压约为 6 V,并发出亮绿色光,亮度为 3700 cd m-2。在 14 V 和 11.75 mA cm-2 时,最大发光效率为 2.0 cd A-1。OLED 器件发出的光为绿色,根据 CIE 色坐标为 (x, y) (0.33, 0.54)。此外,还分别使用循环伏安法、紫外可见吸收法和荧光光谱法对电化学和光学特性进行了研究。