Erbium(III) selenide is an inorganic compound with a chemical formula of Er2Se3.

Erbium(III) selenide can be obtained by the reaction of erbium and selenium: It can also be prepared by reacting erbium oxide and hydrogen selenide at high temperature.

[3] Erbium(III) selenide is an orthorhombic crystal with a Sc2S3 structure and a space group of Fddd.

[2] It reacts with magnesium selenide at 1000 °C to obtain MgEr2Se4.

[4]