What is nickel (ii) selenide?

Nickel (II) selenide is a chemical compound with the formula NiSe. It is a black solid that is insoluble in water. Nickel (II) selenide is a semiconductor and has potential applications in photocatalysis, solar cells, and electronics. It can be synthesized by reacting nickel acetate and selenium powder in an inert atmosphere at high temperature. Nickel (II) selenide has a hexagonal crystal structure and is isostructural with cadmium selenide and zinc selenide. It is a stable compound but can be oxidized under certain conditions to form nickel selenite or nickel selenate. The toxicity of nickel (II) selenide is not well studied, but it is known that nickel and selenium compounds can be harmful if ingested or inhaled in certain quantities.