Surface spin accumulation due to the inverse spin Hall effect in WS2 crystals

Applications of semiconductors in spintronics are being developed and revolutionized to fabricate nanostructures in which the spin current is injected, detected and manipulated. The manifestation of the spin Hall effect (SHE) in semiconductors with a simple geometry is still a challenge to implement in spintronics. In this work, we demonstrate the distinct electrical detection of the inverse spin Hall effect (ISHE) in WS2 multilayer crystals at temperatures ranging from 4.2 K to 300 K. The novel idea of this study is the electrical detection of the ISHE in WS2 using an in-plane spin-polarized current, which is realized using non-ferromagnetic electrodes on the top and bottom surfaces of the WS2 channel. The flow alteration of spin-polarized current results in a polarity change in the inverse spin Hall signal. By analyzing the magnitude of the ISHE, we estimated a spin diffusion length of similar to 250 nm, spin Hall angle of similar to 0.028, spin polarization of similar to 0.20 and spin lifetime of similar to 560 ps in WS,layered crystals at room temperature. The ISHE in layered, 2D materials, including WS2 crystals, provides a new methodology to develop low-power and fast memory devices to write, read and store information.