Modeling the photo-induced inverse spin-Hall effect in Pt/semiconductor junctions

We show that the photon energy dependence of the photo-induced inverse spin-Hall effect (ISHE) signal at Pt/semiconductor junctions can be reproduced by a model that explicitly accounts for the electron spin diffusion length L-s in the semiconductor. In particular, we consider the Pt/GaAs, Pt/Ge, and Pt/Si systems: although optical spin injection and transport of spin-polarized electrons in the conduction band of these semiconductors are ruled by different mechanisms, a simple one dimensional analytical diffusion model, where L-s is the free parameter, can reproduce the ISHE data in all cases. This highlights the potentialities of the photo-induced ISHE spectra as a tool to directly address fundamental spin transport properties in semiconductors. Published by AIP Publishing.