مشخصات پژوهش

The spin‑photo current in single layer stanene and germanene under a linearly polarized light is theoretically investigated based on the tight‑binding Hamiltonian combined with the nonequilibrium Green’s function at room temperature. The results show that by considering the simultaneous effect of the linear illumination and a vertical external electric field without any magnetic exchange element, pure spin‑photo current without charge current is generated in two‑dimensional lattices with a large intrinsic spin–orbit coupling. The necessity of enhanced spin life‑time for detection of spin polarization can be explained by spin‑valley locking concept. Spin‑valley locking arises in buckled two‑dimensional materials as a result of the large spin–orbit coupling and electric‑field reversible valley spin polarization. Equal absorption of the linearly illumination at both valleys with different spin polarization, leads to pure spin‑photo current injection. In addition, an acceptable photoresponsivity has been reported in a broad range of photon energy. The numerical results indicate high quantum efficiency with a maximum of nearly 83% and 50% for stanene and germanene, respectively. This work may pave theoretical reference toward design of new spin‑optoelectronic devices based on satanene and germanene junctions with high performance.