Photogalvanic‐Effect‐Induced Spin‐Polarized Current in Defective Silicane with H Vacancies

Abstract

The spin photocurrent of defective‐silicane‐based photoelectric devices is studied using non‐equilibrium Green's function with first‐principles density functional theory. The calculations reveal that the silicane with H vacancies is a ferromagnetic (FM) semiconductor with a 0.27 μB magnetic moment on the unhydrogenated Si atom. Due to the unique electronic structure, the directions and spin polarizations of the spin photocurrents can be effectively tuned by the polarization/phase angles or the photon energy (Eph) of the incident illumination. Especially, the 100% spin‐polarized photocurrents can be induced, as the Eph is 1.2–2.2 eV for both linearly polarized light (LPL) or circularly polarized light (CPL). Furthermore, the pure spin currents can be obtained by the CPL, as the Eph is 2.6 eV. These results indicate that defective silicane is a promising spintronic material.