Poly(3,6-silafluorene-co-2,7-fluorene)-based high-efficiency and color-pure blue light-emitting polymers with extremely narrow band-width and high spectral stability
作者:Ergang Wang、Chun Li、Yueqi Mo、Yong Zhang、Gang Ma、Wei Shi、Junbiao Peng、Wei Yang、Yong Cao
DOI:10.1039/b609250k
日期:——
A new series of copolymers (PSiFF) based on 3,6-silafluorene and 2,7-fluorene were synthesized via the Suzuki polycondensation. The influences of the 3,6-silafluorene content in the copolymers on the thermal, photophysical, electroluminescence and electrochemical properties were investigated. The incorporation of 3,6-silafluorene into the polyfluorene main chain not only suppressed the long-wavelength emission but significantly improved the efficiency and color purity of the copolymer-based devices. Both fluorene and 3,6-silafluorene took part in π-conjugation of the main chain and the electroluminescence spectra were remarkably blue-shifted with increasing wide bandgap 3,6-silafluorene content. The device based on PSiFF90 with the configuration of ITO/PEDOT : PSS/PVK/polymer/Ba/Al showed a quantum efficiency of 3.34% and a luminous efficiency of 2.02 cd A−1 at a brightness of 326 cd m−2 with CIE 1931 chromaticity coordinates of (0.16, 0.07), which almost match the NTSC standard blue pixel coordinates of (0.14, 0.08). Moreover, the incorporation of 3,6-silafluorene into the polyfluorene main chain significantly improved the spectral stability at annealing. The results indicate poly(3,6-silafluorene-co-2,7-fluorene) could be a promising candidate for blue-emitting polymers of high efficiency and good color purity.
一系列基于3,6-硅氟烯和2,7-氟烯的共聚物(PSiFF)通过铃木聚缩合法合成。研究了共聚物中3,6-硅氟烯含量对热、光物理、发光及电化学性质的影响。将3,6-硅氟烯引入聚氟烯主链不仅抑制了长波长发射,还显著提高了基于共聚物的器件的效率和色彩纯度。氟烯和3,6-硅氟烯均参与主链的π-共轭,随着宽带隙3,6-硅氟烯含量的增加,电致发光光谱显著蓝移。基于PSiFF90的器件配置为ITO/PEDOT:PSS/PVK/聚合物/Ba/Al,在亮度为326 cd m−2时,量子效率为3.34%,光效率为2.02 cd A−1,CIE 1931色度坐标为(0.16, 0.07),几乎与NTSC标准蓝光像素坐标(0.14, 0.08)相匹配。此外,将3,6-硅氟烯引入聚氟烯主链显著改善了退火过程中的光谱稳定性。结果表明,聚(3,6-硅氟烯-co-2,7-氟烯)可能成为高效率且色彩纯度良好的蓝光发射聚合物的有前景的候选材料。