Spin-orbit tuned optoelectronics in magnetized germanene

This study investigates the optoelectronic properties of Germanene, a two dimensional honeycomb lattice material, under the influence of spin–orbit coupling (SOC) and external magnetic fields. Utilizing the Kane–Mele model, we incorporate tight-binding, intrinsic SOC, and Zeeman interactions to describe the electronic band structure. The Green’s function approach is employed to compute optical conductivity, dielectric function, refractive index, and absorption coefficient, highlighting the impact of SOC-induced bandgap opening and magnetic field effects. Our findings reveal that SOC enhances optical absorption and tunes plasmonic excitations, making Germanene a promising candidate for advanced optoelectronic devices, such as photodetectors and optical modulators. Germanene’s operational spectrum spans infrared (0–1.65 eV) to visible (1.65–2 eV), with model-predicted advantages over graphene/silicene including enhanced IR tunability via stronger SOC (43 meV gap) and field-sensitive plasmonics, enabling superior photodetection efficiency and modulation capabilities. The results underscore the potential of Germanene in spintronics and valleytronics, driven by its tunable electronic and optical properties. • SOC induces 43 meV bandgap in germanene, enhancing IR absorption by 20% vs. silicene. • Magnetic fields cause Zeeman splitting, enabling tunable low-frequency plasmonics. • Field-dependent optical conductivity modulates for high-sensitivity photodetectors. • SOC and fields promote valley-polarized absorption for spin/valleytronics devices.