GeP (Germanium Phosphide)

A group IV–V layered van der Waals semiconductor with a low-symmetry monoclinic structure (space group C2/m), built from puckered Ge–Ge and Ge–P bonded sheets. It exhibits pronounced in-plane anisotropy in electrical, optical, and vibrational properties, and is a p-type semiconductor with an indirect, layer-tunable band gap (~0.5 eV in bulk, widening in few-layer form). These features—together with its high theoretical alkali-metal storage capacity—make GeP a promising platform for polarization-resolved photodetectors, anisotropic electronics, and battery anodes.