Synthesis and luminescent properties of GdNbO4:Bi3+ phosphors via high temperature high pressure

This work reports the high-pressure and high-temperature (HP-HT) synthesis of pure monoclinic phase of GdNbO4:Bi3+ phosphors. X-ray diffraction, field emission scanning electron microscopy, transmission electron microscopy, photoluminescence, and IR spectra were utilized to characterize the synthesized phosphors. The crystal structure distortions operated by the pressure leads to tunable emission varying from blue to yellow. A small increase of the probability of non-radiative energy transfer with increase of pressure is observed. It is shown that the efficiency of the energy transfer process is dependent on pressure. The calculations of CIE chromaticity coordinates were performed. •We studied a series of high-pressure behavior of Niobates.•The color of a complex compound often changes from blue to yellow under high-pressure conditions.•The luminescence properties and mechanism are discussed in detail.