优化能量水平对齐以实现高温激发深红色OLED的创纪录效率
Yujie Wu1,2,3, Jiasen Zhang1,2, Deli Li4
1Zhejiang Provincial Engineering Research Center of Energy Optoelectronic Materials and Devices, Ningbo Institute of Materials Technology and Engineering, Chinese Academy of Sciences, Ningbo, 315201, P. R. China. liwei1987@nimte.ac.cn.
Materials horizons
|June 7, 2024
概括
研究人员开发了新的热激子发射器,用于高效的深红色 (DR) 有机发光二极管 (OLED). 这些发射器克服了快速辐射衰变的"能量差距定律",在DR-OLED中实现了高量子产量和外部量子效率.
科学领域:
- 材料科学 材料科学 材料科学
- 有机电子 有机电子
- 光物理学的光学物理学
背景情况:
- "能源差距法"阻碍了深红 (DR) 和近红外 (NIR) 区域的高效光发射,原因是火过程.
- 热激子发射器通过快速辐射衰变提供了一个潜在的解决方案,但需要特定的能量水平配置.
- 在单元 (S1) 和三元 (T2) 激发状态之间实现狭窄的能量差距,T2略高于S1,对于热激发的功能至关重要.
研究的目的:
- 设计和合成新的热激子发射器,以实现高效的DR和NIR发射.
- 研究分子设计,能量水平对齐和光物理性质之间的关系.
- 为了证明这些发射器在非兴奋剂深红色有机发光二极管 (DR-OLED) 中的性能.
主要方法:
- 通过将特定的电子捐赠器 (αTPA, βTPA) 与电子受体 (IPD) 合,合成两个概念验证热激发器,αT-IPD和βT-IPD.
- 光物理性质的表征,包括能量差距 (ΔES和 ΔET),光发光量子产量 (PLQYs) 和聚合诱导辐射 (AIE) 特性.
- 使用合成发射器制造和测试使用非兴奋剂的DR-OLED设备.
主要成果:
- 无论是αT-IPD还是βT-IPD发射器,都表现出狭窄的ΔES,其中T2略高于S1,以及大的ΔET.
- 发射器显示聚合诱导发射 (AIE) 和在晶体状态下有利的分子间相互作用.
- 在非兴奋剂片中实现了68.5% (αT-IPD) 和73.5% (βT-IPD) 的显著PLQY.
- 一个基于βT-IPD的无添加的DR-OLED在667nm时达到15.5%的最大外部量子效率 (EQE).
结论:
- 设计的αT-IPD和βT-IPD分子有效地作为热刺激子发射器起作用.
- 狭窄的ΔES和特定的分子包装有助于高的PLQY和高效的DR发射.
- 实现的15.5%EQE代表了热激发DR-OLED的重大进步,克服了能源差距法限制.
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