Phase transition and optical properties of Ba1-xZnxAl2O4:0.1% Eu3+ prepared via citrate sol-gel method

Undoped and Ba1-xZnxAl2O4:0.1% Eu3+ series (0 ≤ x ≤ 1) were successfully prepared using the citrate sol-gel method. X-ray diffraction (XRD) results revealed that depending on the Zn moles, the prepared samples could be indexed to hexagonal BaAl2O4 and cubic ZnAl2O4 structures. Scanning electron microscopy (SEM) shows that varying Zn moles changes the morphology of the prepared sample. Transmission electron microscopy (TEM) results confirmed the nano-crystallite shape and size of the structures seen in SEM, and the multiphase nature predicted by XRD. The photoluminescence (PL) results showed distinct emission peaks, which were either attributed to the host intrinsic intra-band gap defects or to characteristic transitions within Eu3+ ions. The International Commission on Illumination (CIE) colour coordinates showed that the emission colour can be tuned when varying the Zn mole. •Ba1-xZnxAl2O4:0.1% Eu3+ series was successfully prepared using the citrate sol-gel.•The prepared samples consists of the multiphase.•Morphology highly depends on the Zn moles.•Emissions observed were attributed to the hosts defects and transitions of Eu3+ ions.•The blueish emission colour can be tuned by varying the Zn mole.