Conversion of heat into a spin-current in electron doped silicon can offer a
promising path for spin-caloritronics. Here we create an electron spin
polarization in the conduction band of n-type silicon by producing a
temperature gradient across a ferromagnetic tunnel contact. The substrate
heating experiments induce a large spin signal of 95 μV, corresponding to
0.54 meV spin-splitting in the conduction band of n-type silicon by Seebeck
spin tunneling mechanism. The thermal origin of the spin injection has been
confirmed by the quadratic scaling of the spin signal with the Joule heating
current and linear dependence with the heating power