GeS

Germanium sulfide (GeS) is a layered IV-VI semiconductor compound with a two-dimensional crystal structure similar to black phosphorus, offering tunable bandgap and strong anisotropic optical properties. Primarily of research and emerging-technology interest, GeS is being investigated for applications requiring efficient light absorption and conversion, particularly in flexible and wearable optoelectronic devices where its mechanical flexibility and layer-dependent functionality provide advantages over conventional bulk semiconductors. The material's low exfoliation energy and tunable electronic properties make it a candidate for next-generation photovoltaics, photodetectors, and integrated photonics, though it remains largely in laboratory development rather than established industrial production.