Roles of Structural Disorder and Surface State in Photoluminescence of BaTiO3 Nanoparticles
This work provides an insight on the photoluminescent behaviour of BaTiO3 (BTO) nanoparticles synthesised via a hydrothermal process at 200°C with further heat treatment at 1000°C. The morphology of BTO nanoparticles evolved to pseudo-ellipsoid by tuning the concentration ratio of barium precursors (Ba), oleic acid (OA) surfactant and tert-butylamine (TA) additive. Tunable optical band gaps (3.58–4.06 eV), Urbach tails in UV–Vis absorption spectra and the enhanced intensity of room temperature photoluminescence at violet wavelength (433.7 nm) were observed in BTO nanoparticles. The structural evolution and phase formation indicated that structural disorder and surface state share equal dominant factors for improving the photoluminescence at violet wavelength, tuning optical band gaps and exhibiting Urbach effect in the absorption spectra.