ABSTRACT
Recently, spintronics has expanded its choice of materials to the organic semiconductors (OSCs) [1-3]. OSCs o¥er unique properties toward their integration with spintronics, the main one being the weakness of the spin-scattering mechanisms in OSC. Spin-orbit coupling is very small in most OSCs; carbon has a low atomic number (Z) and the strength of the spin-orbit interaction (SOI) is in general proportional to Z4 [4]. Typical SOI values in OSC are less/about a few meV [5], well below any other characteristic energy, including main vibrational modes. Small spin-orbit coupling implies that the spin polarization of the carriers could be maintained for a very long time. Indeed, spin relaxation times in excess of 10 μs have been detected by various resonance techniques [6,7], and these values compare very favorably (at least 103 times larger) with those obtained with high-performing inorganic semiconductors, such as GaAs [8].
