Our approach to prepare multilayer light emitting devices (LEDs) by low-cost spin-coating techniques is the combination of spin-coating and photo-crosslinking. The oxetane functionality was used as the polymerizable moiety, which was crosslinked in bulk by a cationic mechanism. The resulting films were resistant against solvents used in subsequent spin-coating steps. The synthesis of bis-functionalized hole transporting triarylamines by palladium catalyzed C1N-coupling reaction, their polymerization, characterization, and first application in two-layer blue light emitting OLEDs are presented.

The synthesis and characterization of side-chain polymers functionalized with holetransporting units and photo-cross-linkable groups, which can be used for solution-based preparation of multilayer organic light-emitting devices (OLEDs), are discussed. The concept deals with triarylamine and oxetane-functionalized styrenes, which are copolymerized by radical polymerization. Four different types of hole-transporting monomers were combined with one cross-linkable monomer in two different ratios, yielding two groups of each four polymers (P1A...P4A and P1B...P4B). The polymers were investigated by NMR spectroscopy, molecular weights were determined by GPC with light scattering, and the thermal properties were measured with differential scanning calorimetry (DSC). Optical characterization by UV-vis and fluorescence spectroscopy was performed. Electrochemical and crosslinking characteristics of the copolymers were investigated to proove this strategy's potential in application for modern multilayer polymer OLEDs. Finally, hole-only devices were prepared for evaluation of the semiconductive performance of the materials.

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