Solution-processed high efficiency OLED harnessing a thermally cross-linked hole-transporting layer and exciplex-forming emission layer

J. Mater. Chem. C., 11 (2023) 1056.

https://doi.org/10.1039/D2TC04638E

我們合成了一種新的二咔唑基的施體 BCz3Ph，用於形成激基複合物，作為溶液製程OLED元件的發光層 (EML)。 同時為了增強電洞注入，我們設計了一種同為二咔唑基的熱交聯單體 BCzC4Sy，以在熱聚合後實現耐溶劑的空穴傳輸層 (HTL)。 選擇二咔唑作為 HTL 核心不僅抑制了 HTL 到 EML 的能障，而且還防止了由於 HTL/EML 界面處可能的激基複合物發射而導致的發射光純度變異。

A new dicarbazole-based donor, BCz3Ph, for exciplex formation was synthesized as the emitting layer (EML) of solution-processed OLED devices. To facilitate hole injection into the EML, a new cross-linkable monomer, BCzC4Sy, adopting a dicarbazole core linked to a styrene group by a butyl chain was designed to realize a solvent resistant hole-transporting layer (HTL) after thermal polymerization.  The choice of dicarbazole as the HTL core not only suppresses the HTL-to-EML energy barrier, but also prevents the emission color variation stemming from the possible exciplex emission at the HTL/EML interface.