Magnetic and Spin-Polarized Optical Properties of Co and Mn Adsorbed -GeSe

The structural, electronic, magnetic, and optical properties of Co- and Mn-adsorbed gamma-GeSe have been studied comprehensively via first-principles density functional calculations. It is found that the most stable adsorption configuration is that Co and Mn are on the top of the hexagonal hollow in the second Ge layer. After Co and Mn adsorption, gamma-GeSe becomes magnetic with 1 mu(B) and 3 mu(B) magnetic moment, which mainly comes from mainly the Co(Mn)-d, Ge-s, Ge-p, and Se-p states. In particular, the optical absorption in the low-energy range is greatly enhanced by Co and Mn adsorption and results in interesting spin-dependent absorption in low-energy region due to the strong electron transition at the spin-down channel, which makes them attractive candidates for spin-optoelectronic devices.