Nickel oxide is a chemical compound composed of nickel and oxygen, with the formula NiO. It typically appears as a green or black powder and is used in various applications, including ceramics, glass, and as a catalyst in chemical reactions. Nickel oxide is also important in the production of nickel-based batteries. In addition to its industrial uses, nickel oxide plays a role in electronics, particularly in the manufacturing of thin-film transistors and solar cells. It is known for its semiconductor properties, which make it valuable in the development of advanced electronic devices.