On the Origin of Green Emission Bands in Fluorene‐Based Conjugated Polymers
On the Origin of Green Emission Bands in Fluorene‐Based Conjugated Polymers
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DOI：
10.1002/adfm.200600141
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发表时间：
2007-01
影响因子：
19
通讯作者：
F. Montilla;R. Mallavia
中科院分区：
文献类型：
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作者：
F. Montilla;R. Mallavia
由聚荧烯制成的蓝光发光二极管稳定性较低，在运行中会迅速降解并产生不受欢迎的低能量发射波段(绿色或g波段)。本文报道了聚荧烯降解过程的光谱电化学研究。这些聚合物通过电化学氧化和通过σ键断裂进行还原而失去其电子性质。此外，在电化学还原过程中，观察到在485 nm处形成了有结构的绿色发射带。这个带的位置和形状不同于通常分配给荧酮缺陷的在nm处的无特征带。用傅里叶变换红外光谱对绿光产物进行分离和分析，排除了荧酮的生成。分离出的产物是交联的，其绿色发射可能与分子内准分子的形成有关。
Blue‐light‐emitting diodes made of polyfluorenes have low stability and, under operation, rapidly degrade and produce undesirable low‐energy emission bands (green or g‐bands). A spectroelectrochemical study of the degradation process suffered by polyfluorenes is reported here. These polymers lose their electronic properties by electrochemical oxidation and reduction through σ‐bond breaking. In addition, upon electrochemical reduction, the development of a structured green emission band at 485 nm is observed. The position and shape of this band is different from the usual featureless band at 535 nm assigned to fluorenone defects. The green‐light‐emitting product is isolated and analyzed by Fourier‐transform IR spectroscopy; fluorenone formation is excluded. The isolated product is crosslinked; its green emission is probably related to the formation of an intramolecular excimer.