White light electrophosphorescence from polyfluorene-based light-emitting diodes: Utilization of fluorenone defects
White light electrophosphorescence from polyfluorene-based light-emitting diodes: Utilization of fluorenone defects
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DOI：
10.1021/jp040027v
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发表时间：
2004-05
影响因子：
3.3
通讯作者：
X. Gong;D. Moses;A. Heeger;S. Xiao
中科院分区：
文献类型：
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作者：
X. Gong;D. Moses;A. Heeger;S. Xiao
合成了含1%荧酮的聚(9，9-二辛基-共-荧酮)(PFO-F(1%))作为模型化合物，研究了聚(9，9-二辛基-2，7-二基)中荧酮缺陷的光学和电学效应。光致发光(PL)和电致发光(EL)测试表明，PFO-F(1%)能发出稳定的绿光。PL和EL研究表明，福斯特能量转移到荧酮缺陷上的电荷载流子捕获(随后的荧酮发射)是多荧烯通常观察到的颜色退化的原因。利用PFO-荧酮共聚物(PFO-F)中的“荧酮缺陷”，制备了白色发光二极管。聚合物共混物从含有PfO、PfO-F(1%)和tris[2，5-bis(9，9-dihexylfluoren-2-yl)pyridine-κ2 NC3]Ir-(III)，Ir(HFP)3的溶液中旋转浇注。白光发射电压约为5V，在17V时的亮度(L)为6100cd/m2，在电流密度为8.5 mA/cm2时的发光效率为3cd/A(L=255cd/m2)。该白光具有稳定的色坐标和稳定的色温，具有较高的显色指数。
Poly(9,9-dioctylfluorene-co-fluorenone) with 1% fluorenone, (PFO-F(1%)), was synthesized as a model compound to investigate the optical and electrical effects of fluorenone defects in poly(9,9-dioctylfluoren2,7-diyl), PFO. Photoluminescence (PL) and electroluminescence (EL) measurements demonstrate that PFO-F(1%) emits stable green light. PL and EL studies indicate that Forster energy transfer to and charge carrier trapping on fluorenone defects (with subsequent fluorenone emission) are responsible for the color degradation typically observed with the polyfluorenes. By utilization of "fluorenone defects" in PFO-fluorenone copolymers (PFO-F), white electrophosphorescent light-emitting diodes were fabricated. Polymer blends were spin-cast from solution containing PFO, PFO-F (1%), and tris[2,5-bis(9,9-dihexylfluoren-2-yl)pyridine-κ 2 NC 3 ]iridium-(III), Ir(HFP) 3 . The white emission turns on at approximately 5 V, with a luminance (L) of 6100 cd/m 2 at 17 V. The luminous efficiency is 3 cd/A at current density of 8.5 mA/cm 2 (L = 255 cd/m 2 ). The white light exhibits stable color coordinates and stable color temperature and has a high color rendering index.