Thallium(III) oxide, also known as thallic oxide, is a chemical compound. Its chemical formula is Tl2O3. It has thallium and oxide ions in it. The thallium is in its +3 oxidation state.
Thallium(III) oxide is a white powder. It is very heavy and very toxic. It is a semiconductor. It reacts with acids to make other toxic thallium compounds. It does not dissolve in water.
It is made by oxidation of thallium(I) oxide.
It may be used in solar cells.