溶液加工型多层磷光器件的组装与性能优化

传统小分子磷光器件的发光层由磷光客体掺杂在主体材料中组成，容易被醇类溶剂溶解或破坏，难以通过溶液加工工艺制备高效多层结构。针对这一制约瓶颈，本项目旨在采用Self-Host型树枝状铱配合物作为发光层，发展一种新型溶液加工型多层磷光器件的组装方法。有别于传统小分子物理共混体系，这类主/客体一体化的材料体系可以利用树枝状分子特有的包裹效应，增强发光层对醇类溶剂的抵御能力，从而解决目前多层磷光器件组装过程中的层间互溶问题（发光层和电子传输层），为实现高性能的溶液加工型多层磷光器件开辟出新途径。

In general, it is a big challenge to develop efficient multilayer device structure via solution processes, for the emitting layer (EML) of small-molecule-based phosphorescent OLEDs made of phosphor and host could be easily dissolved or disrupted by alcoholic solvents. To solve this problem, the self-host iridium dendrimers have been adopted as the EML for the fabrication of novel solution-processed multilayer phosphorescent OLEDs in this project. Unlike the physical blend, such dendritic system can withstand the erosion from alcoholic solvents owing to the dendrimer’s characteristic encapsulation effect. As a result, the EML would remain unchanged during the deposition of the upper electron transport layer, which is the key point to realize solution-processed multilayer phosphorescent OLEDs with high performance.