Influence of dopants on spin-charge conversion in GaAs

The practical applications for spintronic semiconductors requires the control of spin to charge current conversion. The ratio of spin current to charge current in a material can be determined from the inverse spin Hall angle ( θ ISHE ) and can be experimentally extracted. However, the reported results on the magnitude and the sign of θ ISHE in various semiconductors are rather diversed in association with the difference in the details of material properties. In this study, we focus on the dopant effects on the θ ISHE of GaAs. We adopted the technique of ferromagnetic resonance driven spin-pumping to accurately determine the θ ISHE in the GaAs single crystals with different type of dopants. We found that the magnitude of θ ISHE is sensitive to the atomic number of dopant ( Z ), but the sign of θ ISHE is independent on the dopant type. In addition, the relationship between θ ISHE and Z follows the Landau-Lifshitz Z 2 scaling.