9
Organic Magnetoresistance and Spin Diffusion in Organic Semiconductor Thin-Film Devices
9.1 Introduction
The field of organic electronics, that is, electronic devices that are based on π-conjugated organic semiconductors, has progressed at a rapid pace and electronics based on organic thin-film materials could soon become a mainstay of semiconductor technology. Recently, commercial products based on organic light-emitting diodes (OLEDs), organic photovoltaic cells (OPV), and organic field-effect transistors (OFETs) have entered on the market. The future may see an even wider range of application for this technology. One specific area that organic semiconductors may be applied to is spintronics.
The study of electron-spin transport through metallic and semiconducting devices is an extremely active field called spintronics, because of the rich physics involved and the important applications in the area of magnetic sensors. Spintronics deals with controlling and utilizing the electron-spin degree of freedom through a variety of spin-dependent phenomena. The spin valve is the principal spintronic device and consists, in its most basic form, of two ferromagnetic electrodes separated by a nonmagnetic spacer layer (Figure 9.1). The two ferromagnetic electrodes are chosen to exhibit two distinct switching fields, and the device can be switched between a parallel and antiparallel magnetization configuration using an applied magnetic field . The significant difference ...