Synthesis of laterally attached side-chain liquid crystalline poly(p-phenylene vinylene) and polyfluorene derivatives for the application of polarized electroluminescence
Synthesis of laterally attached side-chain liquid crystalline poly(p-phenylene vinylene) and polyfluorene derivatives for the application of polarized electroluminescence
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DOI：
10.1016/j.polymer.2006.10.002
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发表时间：
2006-11
期刊：
影响因子：
4.6
通讯作者：
Yung-Hsin Yao;Sheng-Hsiung Yang;Chain‐Shu Hsu
中科院分区：
文献类型：
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作者：
Yung-Hsin Yao;Sheng-Hsiung Yang;Chain‐Shu Hsu
合成并表征了两个含有侧链连接的五(对苯撑)介元的聚对苯乙撑和聚荧衍生物(PPV1-PPV4和PF1-PF5)。这些聚合物表现出向列型液晶行为。用紫外-可见吸收光谱和光致发光光谱研究了聚合物的光学性质，并制备了以聚(乙二氧基噻吩聚苯乙烯磺酸)(PEDOT-PSS)为取向层的偏振电致发光器件。在聚对苯乙炔衍生物系列中，聚合物PPV4具有最好的电致发光性能。在4V下发射波长为588 nm的黄光。在9V时，最大亮度约为1337cd/m2，偏振比为2.6。在另一个系列的聚荧烯衍生物中，PF4具有最好的电致发光性能，偏振比为12.4，最大发光强度为1855cd/m2。在偏振白光的情况下，由于将少量的PF4和PF5与主体聚合物PF2混合，获得了高达10.2的偏振比和2454cd/m2的最大亮度。取向的薄膜表现出明显的偏振率，这意味着聚合物显示出潜在的线偏振LED应用。
Two series of poly(p-phenylene vinylene) and polyfluorene derivatives (PPV1–PPV4 and PF1–PF5) containing laterally attached penta(p-phenylene) mesogenes were synthesized and characterized. These polymers show nematic liquid crystalline behavior. The optical properties of the polymers were investigated by UV–vis absorption and photoluminescence spectrometers and these polymers were fabricated to form the polarized electroluminescent devices using poly(ethylenedioxythiophene)–poly(styrene sulfonic acid) (PEDOT–PSS) as an alignment layer. In the series of poly(p-phenylene vinylene) derivatives, polymer PPV4 offered the best EL device performance. It emitted yellow light at 588nm at 4V. The maximum brightness was about 1337cd/m2at 9V with a polarized ratio of 2.6. In another series of polyfluorene derivatives, PF4 offered the best EL device performance with the polarized ratio of 12.4 and a maximum luminescence of 1855cd/m2. In the case of polarized white light, as a consequence of blending small amount of PF4 and PF5 with a host polymer PF2, polarized ratio of up to 10.2 and a maximum brightness of 2454cd/m2have been attained. The aligned films exhibited pronounced polarized ratio, implying that the polymers exhibit potential for linearly polarized LED application.