Simultaneous enhancement of the carrier mobility and luminous efficiency through thermal annealing a molecular glass material and device
Simultaneous enhancement of the carrier mobility and luminous efficiency through thermal annealing a molecular glass material and device
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DOI：
10.1039/c2jm34663j
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发表时间：
2012-09
影响因子：
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通讯作者：
S. Xue;Liang Yao;Suijun Liu;Cheng Gu;F. Shen;Weijun Li;Hui Zheng;Hongbin Wu;Yuguang Ma
中科院分区：
文献类型：
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作者：
S. Xue;Liang Yao;Suijun Liu;Cheng Gu;F. Shen;Weijun Li;Hui Zheng;Hongbin Wu;Yuguang Ma
分子2,5,2 ',5 ' -四（2,2-二苯基乙烯基）联苯（TDPVBi）在有机溶剂中具有优异的溶解度，在固体状态下具有完全非晶（玻璃态）的性质和强的蓝色发射，使其具有制备溶液加工小分子器件的潜力。为了进一步提高TDPVBi薄膜的质量，对从溶液中制备的原始薄膜进行了热处理，并证明了该方法是修复原始薄膜中存在的缺陷（如针孔）的有效方法。在玻璃化转变温度（Tg）附近进行热处理后，薄膜表面形貌趋于平整致密。器件特性表明，热退火可以同时提高空穴迁移率和发光效率。在120℃的温度下热退火后，发光效率达到4.60 cd A−1（对应的外量子效率为~ 3.0%），是未退火器件的两倍。
The molecule 2,5,2′,5′-tetrakis(2,2-diphenylvinyl)biphenyl (TDPVBi) shows excellent solubility in organic solvents, a fully amorphous (glass state) property and strong blue emission in the solid state, endowing it with potential to fabricate solution-processed small-molecular devices. To further improve the quality of TDPVBi films, thermal annealing of method was performed for the pristine films, as prepared from solution, and proved to be an efficient way to repair the defects (e.g. pinhole) that exist in the pristine films. It is found that the films tend to become compact with level surface morphology after thermal annealing at a temperature around their glass transition temperature (Tg). The device characteristics show that thermal annealing induces a simultaneous enhancement of the hole mobility and luminous efficiency. The luminous efficiency reaches 4.60 cd A−1 (corresponding external quantum efficiency of ∼3.0%) after thermal annealing at a temperature of 120 °C, which is double that of the device without annealing.