Room Temperature Spin Accumulation Effect in Boron Doped Si Created by Epitaxial Fe3Si/p-Si Schottky Contact

Resumo

To study spin-dependent transport phenomena in Fe₃Si/p-Si structures we fabricated 3-terminal planar microdevices and metal/semiconductor diode using conventional photolithography and wet chemical etching. I‒V curve of prepared diode demonstrates rectifying behavior, which indicates the presence of Schottky barrier in Fe₃Si/p-Si interface. Calculated Schottky barrier height is 0.57 eV, which can provide necessary conditions for spin accumulation in p-Si. Indeed, in 3-terminal planar device with Fe₃Si/p-Si Schottky contact Hanle effect was observed. By the analysis of Hanle curves spin lifetime spin diffusion length in p-Si were calculated, which are 145 ps and 405 nm, respectively (at T = 300 K). Spin lifetime strongly depends on temperature which can be related to the fact that spin-dependent transport in our device is realized via the surface states. This gives a perspective of creation of spintronic devices based on metal/semiconductor structure without need for forming tunnel or Schottky tunnel contact.