Spectroscopic and electrical characteristics of highly efficient tetraphenylsilane-carbazole organic compound as host material for blue organic light emitting diodes
Spectroscopic and electrical characteristics of highly efficient tetraphenylsilane-carbazole organic compound as host material for blue organic light emitting diodes
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DOI：
10.1016/j.orgel.2009.07.020
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发表时间：
2009-11-01
影响因子：
3.2
通讯作者：
Chen, Chin-Ti
中科院分区：
文献类型：
--
作者：
Tsuboi, Taiju;Liu, Shun-Wei;Chen, Chin-Ti
研究了双（3.5-二（9 H-咔唑-9-基）苯基）二苯基硅烷（SimCP 2）的热学、电学和光谱性质。SimCP 2作为主体材料制备双（4，6-二氟苯基吡啶）吡啶甲酸铱（Firpic）蓝光发光体时，表现出17.7%的外量子效率和24.2lm/W的功率效率。将它们与1，3-双（9-咔唑基）苯（mCP）和3，5-双（9-咔唑基）四苯基硅烷（SimCP）进行了比较，这两种硅烷也被用作蓝光发射体的主体。SimCP 2具有最高的玻璃化转变温度（148 ℃），并且在形态上更稳定。电子和空穴的迁移率分别为4.8 × 10（-4）cm（2）V（-1）s（-1）和2.7 × 10（-4）cm（2）V（-1）s（-1），电场为9 × 10（4）V cm（-1）。在344 nm处观察到零声子S_1发射带，而在412 nm处观察到T（1）发射带，即，该材料保持了3.56eV的宽带隙和3.01eV的高T（1）三重态能量的特性。从T（1）发射与S（1）发射的强度比可以看出，SimCP 2的系间穿越率小于mCP和SimCP。从这些结果中，我们阐明了为什么SimCP 2上级mCP和SimCP作为有机发光二极管中蓝色磷光发射体的主体材料的原因。(C)2009爱思唯尔有限公司版权所有。
Thermal, electrical and spectroscopic properties have been studied for bis(3.5-di(9H-carbazol-9-yl) phenyl)diphenylsilane (SimCP2) which has exhibited high external quantum efficiency of 17.7% and power efficiency of 24.2 lm/W when it is used as host material for iridium bis(4,6-difluorophenypy ridinato)picolate (Firpic) blue emitter. They are compared with 1,3-bis (9-carbazolyl) benzene (mCP) and 3,5-bis (9-carbazolyl) tetraphenylsilane (SimCP) which have been also used as host for blue emitters. SimCP2 exhibits a highest glass transition temperature (148 degrees C) and is morphologically more stable. The electron and hole mobilities are higher (4.8 x 10(-4) and 2.7 x 10(-4)cm(2)V(-1) s(-1), respectively, at electric field of 9 x 10(4) V cm(-1)) than those of mCP and SimCP. The zero-phonon S, emission band is observed at 344 nm, while the T(1) emission band at 412 nm, i.e., this material preserves the characteristics of wide band-gap of 3.56 eV and high T(1) triplet energy of 3.01 eV. From the intensity ratio of the T(1) emission to the S, emission, it is suggested that the intersystem crossing rate is smaller for SimCP2 than for mCP and SimCP. From these results, we clarify the reasons why SimCP2 is superior to mCP and SimCP as the host material for blue phosphorescence emitter in organic light emitting diodes. (C) 2009 Elsevier B.V. All rights reserved.