New materials for organic light emitting diodes and new matrix system for next generation photoresist

Abstract

Part I. New Materials for Organic Light-Emitting Diodes (OLEDs) Firstly, a novel organic light-emitting compound based on tris(8-hydroxyquinoline)aluminum was synthesized. A dendron type of solubilizing group was substituted to enhance solubility in common organic solvents. The structure of the synthesized compound was characterized by $^1H$ NMR and its absorbance and photoluminescence properties were investigated both in solution and solid states. The synthesized compound showed excellent solubility in common organic solvents such as tetrahydrofuran, dichloromethane, and chloroform while maintaining its luminescent property. Secondly, we have designed a new blend system in which the emitting polymeric host is cross-linked with the charge-transporting dopant. A fluorene-based photo-patternable polymer, poly(2,7-(9,9-dioctyl-fluorene)-co-2,7-(9-methyl-9-(3-methyl-oxetan-3-ylmethoxy-propyl)-fluorene)] (PF-OF), was synthesized through palladium-catalyzed Suzuki polymerization. As reactive charge-transporting molecules, oxetane-functionalized aryl amine and aromatic oxadiazole were synthesized. Devices constructed from cross-linked PF-OF with charge-transporting molecules showed better color purity of the blue emission and device performances that were two-to-three times better than those of pure PF-OF at the same condition. Part II. New Matrix System for Next Generation Photoresist Firstly, a novel organic-inorganic hybrid resist containing a trimethoxysilane cross-linker, poly (MPMS-co-GBLMA), was successfully synthesized for deep UV lithography. This new resist system does not need the post-exposure baking step thereby eliminating the post-exposure delay problems. Protons generated from photo acid generators upon UV irradiation initiate the condensation of methoxysilane groups resulting in siloxane network in the exposed regions of the resist film creating negative-tone images. The formed siloxane enables the resist to be used as a bilayer r...