Graphene is a one‐atom thick two‐dimensional monolayer material with amazing physical properties. Carrier mobilities higher than those of silicon raised great expectations for disruptive carbon‐based electronics. Graphene represents the ideal two‐dimensional electron gas with negligible spin‐orbit coupling (SOC) as well as hyperfine interaction, which are prerequisites for long electron spin lifetimes. Thus graphene is very appealing for applications in spintronics. The essential benchmark for spintronics devices, i.e. long electron spin lifetimes, has been theoretically predicted on the order of 1 ms. Experimental work using spin‐FET (Field Effect Transistor) or nonlocal spin‐valve measurement devices yielded early on spin lifetimes in the ps range. In 2011 we reached at least 2 ns at room temperature. It was concluded that extrinsic effects are responsible for this shortcoming due to imperfect device technology (exfoliation and handling in air; imperfect tunnel barriers for spin injection from ferromagnets into graphene; charged impurities inducing extrinsic SOC fields). Recent improvements of the device concept, e.g., by “flattening” graphene on top of an h‐BN flake, yielded at room temperature an increase of the carrier mobilities from 1.000 to 20.000 cm2/Vs, spin lifetimes of 12 ns and spin diffusion lengths of 31 μm. These results are encouraging, but yet leave room for improvement and alternative concepts. Our findings rule out previous scalings of spin lifetime vs. momentum scattering time or mobility, which favored a D’yakonov‐Perel’ spin scattering mechanism.
