Electrochemical cross-linking of polyvinylcarbazole (PVK) onto carbazole SAM modified ITO substrates for organic light emitting diode devices

摘要

Poly(N-vinylcarbazole) or PVK materials have been extensively studied for various electrochemical and photochemical applications. Specifically, PVK shows good hole-transport properties for organic electro luminescent devices (OLED). Recently, we have investigated the conversion of "precursor polymers" to form highly modified conjugated polymers and network films on conducting surfaces. This approach consists of a polymer precursor, which by design contains pendant electroactive monomer units. Electropolymerization or chemical oxidation results in a conjugated polymer network having both inter- and intra-molecular cross-linking possibilities between the pendant monomer units. The films formed are characterized by high optical quality (transparency), uniform coverage, good adhesion, smoothness in morphology, and control of ion permeability. Moreover, PVK can be considered as a "precursor polymer" for the formation of the conjugated Polycarbazole (PCz). However, residual ion species due to electrochemical polymerization can be problematic for some actual device applications. Recently, we have reported the electrochemical polymerization and cross-linking properties of PVK as a "precursor polymer" together with copolymerization of carbazole monomers. The details of this polymerization and cross-linking process have been reported elsewhere.