Presence of metal-oxide interface enhanced photoluminescence from In–In2O3 core–shell nanorods

Abstract

The photoluminescence (PL) properties of indium oxide (IO) and In–In₂O₃ core–shell nanorods have been studied at different temperatures in order to understand the role of metal-oxide interfaces and defects on PL emission. The GAXRD spectra confirm the presence of In phase in the core–shell nanorods and STEM-EDX results show that the core of the nanorods is filled with In metal. The Raman and STEM-EDX results show that the core–shell nanorods are more oxygen deficient and indium-rich as compared to IO nanorods. Further comparison of the two samples shows that In–In₂O₃ core–shell nanorods have relatively intense PL emission, large increase in PL intensity with decreasing sample temperature, and the observation of a near band edge emission. This is due to the presence of an In-rich and oxygen deficient In–In₂O₃ interface and the passivation of defects because of the presence of hydrogen during the synthesis of the IO core–shell nanorods. The enhanced PL emission in the core–shell nanorods may have potential applications in future optoelectronics.