Pi-conjugated organoboron polymers in thin-film organic electronic devices

Abstract

Pi-conjugated organoboron polymers for use in thin-film organic polymer electronic devices. The polymers contain aromatic and or unsaturated repeat units and boron atoms. Pi-conjugated organoboron polymers which are end capped, derivatized with solubilizing groups or both exhibit improved solubility and handling properties beneficial for the formation of thin films useful for device fabrication. The vacant p-orbital of the boron atoms conjugate with the pi-conjugated orbital system of the aromatic or unsaturated monomer units extending the pi-conjugation length of the polymer across the boron atoms. The pi-conjugated organoboron polymers are electron-deficient and, therefore, exhibit n-type semiconducting properties, photoluminescence, and electroluminescence. The invention provides thin-film organic polymer electronic devices, such as organic photovoltaic cells (OPVs), organic diodes, organic photodiodes, organic thin-film transistors (TFTs), organic field-effect transistors (OFETs), printable or flexible electronics, such as radio-frequency identification (RFID) tags, electronic papers, and printed circuit elements, organic light-emitting diodes (OLEDs), polymer light-emitting diodes (PLEDs), and energy storage devices employing the pi-conjugated organoboron polymers. In OLED and PLED applications these materials are used as the electron transport layer (ETL) to improve device efficiency. The polymers which exhibit photo- and electroluminescence are also useful as light-emitting material in PLEDs.