Large switchable photogalvanic effect and tunable spin transport in sliding ferroelectric bilayer SiC nanoribbons

Abstract

The photogalvanic effect (PGE) in ferroelectric materials holds great promise for nonvolatile memory and spintronic devices. Nevertheless, it remains challenging to acquire ferroelectric nanoribbons that concurrently exhibit prominent visible-light response, high PGE intensity, and a large switchable ratio. Herein, we perform quantum transport simulations to investigate the PGE properties of bilayer zigzag silicon-carbon nanoribbons (ZSiCNRs). Interlayer sliding induces three typical stacking models, namely AA, AB and AC. AA stacking exhibits only weak spatial inversion symmetry breaking, whereas AB and AC stacking break this symmetry strongly via interlayer slip. This produces a polarization-angle-dependent photocurrent under linearly polarized light and enables multi-parameter performance tuning. Crucially, stacking mode, magnetic order and oblique incident angle jointly modulate the photocurrent and switching ratio. Specifically, the AC-antiparallel configuration (APC) achieves the optimal photocurrent of ∼17.63 a02/photon at 2.8 eV under 45° oblique incidence, while a large switching ratio up to 113.49 is achieved under the parallel configuration (PC), both outperforming most reported ferroelectric PGE systems. Notably, AC stacking supports fully spin-polarized current, while AB stacking enables pure spin current, realizing versatile spin current modulation via structural engineering. This work reveals excellent switchable PGE performance and tunable spin transport of sliding ferroelectric bilayer ZSiCNRs, offering guidance for advanced nonvolatile optoelectronic and spintronic devices.