Narrow-band near-infrared photocurrent enhancement via toroidal dipole resonance in Si 1− x Ge x nanodisk arrays

≈ 0.125) enhances absorptance more than threefold and increases photocurrent up to 3.4 times compared with pure Si metasurfaces. This study demonstrates that alloy engineering provides a practical route to achieve critical coupling and maximize photocurrent in Si-based metasurfaces operating in the NIR region.