Strong Near‐Infrared Photoluminescence Emission of (003)‐Oriented MgTiO 3 Thin Films

In this study, ilmenite‐ MgTiO 3 films were sputtered on p ‐type Si (111) substrates and the extrinsic effects, such as grain size, crystallinity, and orientation of photoluminescence ( PL ) properties of the films are discussed. To reduce the effect of oxygen vacancies (act as shallow defects) on PL emissions in the films, oxygen ( O 2 ) was introduced as the sputtering gas and the excitation light source (λ = 532 nm) which has a corresponding energy ( h ν = 2.33 eV) below the shallow defect states was used. In this study, intense near‐infrared ( NIR ) PL emission centered at 810.1 nm at room temperature can be observed when the MgTiO 3 thin films exhibit the preferred (003)‐orientation and accompanied by the presence of hexagon‐shaped grains. In this study, the experiment results reveal that the NIR emission intensity of MgTiO 3 films highly depend on crystal orientation and/or grain morphology.