Studies of spin related processes in fullerene C60 devices

We have investigated spin related processes in fullerene C-60 devices using several experimental techniques, which include magnetic field effect of photocurrent and electroluminescence in C-60-based diodes; spin polarized carrier injection in C-60-based spin-valves; and pure spin current generation in NiFe/C-60/Pt trilayer devices. We found that the curvature-related spin orbit coupling' in C-60 plays a dominant role in the obtained spin-related phenomena. The measured magneto-photocurrent and magneto-electroluminescence responses in C-60 diodes are dominated by the difference in the g-values of hole and electron polarons in the fullerene molecules. We also obtained giant magneto-resistance of approximate to 10% at 10 K in C-60 spin-valve devices, where spin polarized holes are injected into the C-60 interlayer. In addition, using the technique of spin-pumping in NiFe/C-60/Pt trilayer devices with various C-60 interlayer thicknesses we determined the spin diffusion length in C-60 films to be 13 +/- 2 nm at room temperature.