Organic luminescent devices and magnetoelectronics

Developments in magnetoelectronics are advancing by combination of once disparate areas of research in magnetic materials, semiconductor electronics, and optoelectronics. We explore the integration of magnetic materials with organic semiconductors. Because small spin-orbit coupling in these materials minimizes spin relaxation, they may be useful in spintronic applications. Motivated by a theoretical investigation into spin-dependent exciton formation that predicts a magnetoluminescence valve effect, we attempt to manipulate spin-polarized holes and electrons in an effort to generate magnetic field dependent luminescence in organic light emitting diodes (OLEDs). We have fabricated various functional OLEDs consisting of ferromagnetic electrodes sandwiching a organic semiconducting bilayer, thus demonstrating that hole and electron injection from magnetic electrodes is possible. However, magnetic transition metal anodes produce higher turn-on voltages and significantly reduced lifetimes compared to indium-tin-oxide based OLED's. (C) 2003 American Institute of Physics.