Optimized spin-injection efficiency and spin MOSFET operation based on low-barrier ferromagnet/insulator/n-Si tunnel contact

Abstract

We theoretically investigate the spin injection in different FM/I/n-Si tunnel contacts by using the lattice NEGF method. We find that the tunnel contacts with low barrier materials such as TiO${}_2$ and Ta${}_2$O${}_5$, have much lower resistances than the conventional barrier materials, resulting in a wider and attainable optimum parameters window for improving the spin injection efficiency and MR ratio of a vertical spin MOSFET. Additionally, we find the spin asymmetry coefficient of TiO${}_2$ tunnel contact has a negative value, while that of Ta${}_2$O${}_5$ contact can be tuned between positive and negative values, by changing the parameters.

References in corpus (2)

• Semiconductors between spin-polarized source and drain
• General Green's function formalism for layered systems: Wave function approach