Native defects determine phase-dependent photoluminescence behavior of Eu2+ and Eu3+ in In2O3 nanocrystals

Abstract

We demonstrate the coexistence of Eu²⁺ and Eu³⁺ in corundum and bixbyite-type colloidal In₂O₃ nanocrystals. The emission properties of dopants in both oxidation states are determined by their interaction with native defects, and are dramatically different in the two nanocrystal phases. This difference arises from the smaller nanocrystal size and higher defect density in metastable corundum-type nanocrystals.