An efficient bis(2-phenylquinoline) (acetylacetonate) iridium(III)-based red organic light-emitting diode with alternating guest:host emitting layers
An efficient bis(2-phenylquinoline) (acetylacetonate) iridium(III)-based red organic light-emitting diode with alternating guest:host emitting layers
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DOI：
10.1016/j.orgel.2008.12.004
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发表时间：
2009-04
影响因子：
3.2
通讯作者：
Y. Divayana;X. W. Sun
中科院分区：
文献类型：
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作者：
Y. Divayana;X. W. Sun
我们报道了一种高效的电磷光双（2-苯基喹啉）（乙酰丙酮）铱（III） [Ir(2-phq)2(acac)]基红色有机发光二极管。发射层由Ir(2-phq)2（acac）的周期性薄层组成，该薄层被4,4 ' -双（咔唑-9-基）联苯的主材料隔开。为获得最佳性能，对主、客体厚度分别进行了优化。在亮度为10和100cd/m2时，电流效率最高可达16.2cd/ a，分别降至15和11cd/ a。通过减小主层厚度，进一步提高了功率效率。获得了最大功率效率为8.3lm/W的器件。我们还发现Ir(2-phq)2（acac）中的浓度猝灭主要是由分子聚集引起的。无辐射Förster工艺的激子猝灭很小，Förster半径小于1.8nm。
We report a highly efficient electrophosphorescent bis(2-phenylquinoline) (acetylacetonate) iridium(III) [Ir(2-phq)2(acac)]-based red organic light-emitting diode. The emission layer consists of a periodic thin layer of guest material of Ir(2-phq)2(acac) separated by host material of 4,4′-Bis(carbazol-9-yl)biphenyl. The guest and host thicknesses were optimized independently to obtain the best performance. The current efficiency reaches to a maximum of 16.2cd/A then drops to 15 and 11cd/A at brightness of 10 and 100cd/m2, respectively. By reducing the thickness of the host layer, the power efficiency was further improved. Device with a maximum power efficiency of 8.3lm/W was obtained. We also found that the concentration quenching in Ir(2-phq)2(acac) is dominated by molecular aggregation. Excitonic quenching by radiationless Förster process is miniscule with Förster radius smaller than 1.8nm.