Fig. 2: Identification of oxygen defects.

a O1s XPS spectra of In2O3 and In-Em In2O3. b CO2-TPD profiles of In2O3, In-Em In2O3, and In-Em In2O3(HCl) with HCl etching. c ESR spectra of In2O3 and In-Em In2O3 at 100 K in the dark and under light irradiation. d Lifetimes (τ) of positrons in PAS spectra of In2O3 and In-Em In2O3. e Model of distribution and structure of oxygen defects of In-Em In2O3.