Bias-dependent electrical spin generation in Fe3Si/GaAs: Consistent behavior in the three-terminal, non-local, and local spin valve geometries

Many spintronic device concepts rely on the efficient electrical generation of a spin accumulation inside a semiconductor (SC) using the interface with a ferromagnetic metal (FM). The application of a reverse or forward bias voltage to an FM/n-type SC hybrid contact leads to the generation of spin-polarized electrons in the SC via spin injection or extraction, respectively. Frequently employed lateral transport structures include the non-local and the three-terminal (3T) geometries. However, the results obtained in the 3T geometry are often found to be inconsistent with the expectations derived from the well-established detection of spin signals in the non-local spin valve (NLSV) configuration [1,2]. Reports on spin transport in the technologically more relevant two-terminal arrangement of the local spin valve (LSV) are scarce due to the difficulty to fulll the specific requirements on the device parameters [3]. Here, we demonstrate spin transport for a FM/SC system with a particularly favorable I-V characteristic in both the NLSV and LSV configurations. In addition, our results obtained in the 3T configuration are consistent with the spin-transport characteristics in NLSV and LSV structures.