Tin selenide, also known as stannous selenide, is an inorganic compound with the formula SnSe. Tin(II) selenide is a typical layered metal chalcogenide as it includes a group 16 anion (Se2−) and an electropositive element (Sn2+), and is arranged in a layered structure. Tin(II) selenide is a narrow band-gap (IV-VI) semiconductor structurally analogous to black phosphorus. It has received considerable interest for applications including low-cost photovoltaics, and memory-switching devices.