Color tunable organic light-emitting diodes have intrigued many application fields, such as smart lighting and information encryption. In this study, we propose a simple structure based on interfacial charge transfer complexes (CTCs) with double donors and single acceptors for achieving color tunability. Through embedding a second donor between the primary donor and the acceptor, the emission of devices can be well-tuned by simply controlling the applied voltage. The calculated frontier molecular orbitals of constituted monomers and heterodimers via density function theory confirm the formation of CTCs between the donors and acceptor. Importantly, the highest occupied molecular orbital level and charge carrier mobility of the second donor are crucial to realize widely adjustable spectra with the voltage. With this strategy, the device incorporating 1,3-di(9H-carbazol-9-yl)benzene as the second donor and 4,4′,4″-tris[(3-methylphenyl)phenylamino] triphenylamine as the primary donor exhibits the largest color shift. The CIE coordinates span from (0.52, 0.46) at 4 V to (0.29, 0.26) at 10 V. These findings shed light on the fact that the double-donor-strategy is feasible for fulfilling large-scale color tunability of CTC-based organic light-emitting diodes and is beneficial to simplify the fabrication process.

中文翻译：

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基于双供体界面电荷转移络合物的大规模彩色可调谐OLED的成果及机理


可调谐彩色有机发光二极管引起了许多应用领域的兴趣，例如智能照明和信息加密。在这项研究中，我们提出了一种基于界面电荷转移复合物 （CTC） 的简单结构，具有双供体和单受体，以实现颜色可调性。通过在初级施主和受体之间嵌入第二个施法体，只需控制施加的电压即可很好地调谐器件的发射。通过密度函数理论计算的构成单体和异二聚体的前沿分子轨道证实了供体和受体之间 CTC 的形成。重要的是，第二个供体的最高占据分子轨道水平和电荷载流子迁移率对于实现电压的广泛可调光谱至关重要。通过这种策略，将 1,3-二（9H-咔唑-9-基）苯作为第二供体，将 4,4′，4“-三[（3-甲基苯基）苯胺] 作为主要供体的装置表现出最大的色偏。CIE 坐标范围从 4 V 时的 （0.52， 0.46） 到 10 V 时的 （0.29， 0.26）。这些发现揭示了这样一个事实，即双供体策略对于实现基于 CTC 的有机发光二极管的大规模颜色可调性是可行的，并且有利于简化制造过程。