Hydrogenation process enhances radiation‑stability of ZnO, Ga2O3 and TiO2

Abstract

Synthesizing metal oxide semiconductors with radiation hardness are of significance for their potential application in harsh radiative environments. Herein, ZnO, Ga2O3 and TiO2, which have different cation/anion stoichiometric ratio, are reductive annealed to explore the influence of hydrogenation on radiation resistance of oxide semiconductors, combined with comprehensive characterizations. Results found that while hydrogenation created massive O-deficient defects in all of the three oxides, distinct grain growth and aggregation are only appeared in ZnO and in TiO2. Interestingly, compared with the slightly augmented radiation stability of ZnO and TiO2 after hydrogenation, prominent improvement of the radiation stability of Ga2O3 is observed. Detailed analysis illustrated that the enhancement of radiation tolerance in hydrogenated Ga2O3 can be attributed to the introduction of O-deficient defects, whereas in ZnO and in TiO2 the contribution of O-deficient defects to the radiation hardness are offset considerably by the reduction of grain surfaces/interfaces, which also acts as energy sink during irradiation. Therefore, we conclude that both of grain size and oxygen deficient defects play vital roles in tuning the radiation tolerance of metal oxide semiconductors