Indium oxide (also known as indium sesquioxide, or In2O3) is a yellow colored powder. It is a stable ceramic-like material that is insoluble in water. Indium oxide is an n-type semiconductor and thus can be used as a resistive element in integrated circuits. It also is used to form heterojunctions with materials like p-InP, n-GaAs, n-Si, and other semiconductors.
Other applications include glass (as a color additive), alkaline batteries (to suppress gas formation), and high current electrical switches and contacts (as an anti-arcing additive).