Silicene spintronics: Fe(111)/silicene system for efficient spin injection

Silicene is an emerging 2D material with advantages of high carrier mobility, compatibility with the silicon-based semiconductor industry, and the tunable gap by a vertical electrical field due to the buckling structure. In this work, we report a first-principles investigation on the spin injection system, which consists of a Fe(111)/silicene stack as the spin injector and pure silicene as the spin channel. An extremely high spin injection efficiency (SIE) close to 100% is achieved. The partial density of states of Fe layers in the Fe(111)/silicene stack shows that spin-down states dominate above the Fermi level, resulting in a negligible spin-up current and high SIE. The transmission spectra have been investigated to analyze the spin-resolved properties. The spin injection system based on silicene is promising for the efficient silicon-based spintronics devices such as switching transistors.