Room temperature spin injection into SiC via Schottky barrier

Abstract

Electrical spin injection into and spin extraction from a wide-bandgap semiconductor SiC at room temperature were demonstrated via Schottky junctions. The spin relaxation time of SiC could reach 300 ps, overwhelming that of Si with similar carrier density due to the smaller atomic number. We also found that there existed two channels in SiC/CoFeB Schottky junctions for spin relaxation, one from bulk SiC and the other from interfacial defect states within the barrier whose spin relaxation times were about 1 ns. The bias condition controlled transport channels via bulk or defect states within the barrier and then affected the effective spin relaxation process. Realization of spin injection into SiC shed light on spintronics of wide-bandgap semiconductors such as spin-resolved blue light emitting diodes and high power/temperature spintronics.

Electrical Spin Injection into the 2D Electron Gas in AlN/GaN Heterostructures with Ultrathin AlN Tunnel Barrier

“…An obvious change in signal amplitude and FWHM should have been observed if spins were captured by those localized states. [ 33,38 ] Careful measurements with different amplitudes of AC were conducted. Figure 3b shows the Hanle signals with various biases at 35 K. Characterized by the FWHM, τ s shows weak dependence on bias.…”

Spin relaxation induced by interfacial effects in n-GaN/MgO/Co spin injectors

“…) where E b is the tunneling barrier. 13,25 It turns out that AT 2 could be regarded as T-insensitive near room temperature 13 compared with the exponential term. Under this approximation, ln(I s ) has a linear dependence on 1/T.…”

“…Considering multistep sequential tunnelling process inside Schottky barrier region via the localized interfacial states as reported in ref. 13, the effective s s extracted from Hanle measurement should be actually an averaged spin relaxation time s int of the localized interfacial states and s bulk of the bulk. 13,16 Fortunately, s s is close to s int under low negative bias voltages and becomes closer to s bulk under higher negative bias voltages due to different tunnelling channels under different bias conditions.…”

“…6,7 Spin-tunnelling barriers, such as MgO and Al 2 O 3 (ref. [8][9][10][11][12] or Schottky barriers, [13][14][15] are wildly used to overcome the conductance mismatch and increase the spin injection efficiency. However, the localized interfacial states inside the tunnelling barriers may trap spin-polarized electrons 13,16,17 and block spin transport into bulk region.…”

“…[8][9][10][11][12] or Schottky barriers, [13][14][15] are wildly used to overcome the conductance mismatch and increase the spin injection efficiency. However, the localized interfacial states inside the tunnelling barriers may trap spin-polarized electrons 13,16,17 and block spin transport into bulk region. Furthermore, the interfacial effects, including localized interfacial states, interfacial random magnetostatic eld induced by roughness, 18 and the Rashba SOC eld induced by the interface band bending, 19,20 signicantly affect the spin relaxation process, whereas this topic has rarely been investigated systematically, 13,16 especially for wide-bandgap semiconductors.…”