Tunable multicolor luminescence via energy transfer in CaLaGaO4:Tb3+, Eu3+single-phase phosphors

초록

A multicolor tunable CaLaGaO4:Tb3+, Eu3+ phosphors has been synthesized using typical solid-state reaction technique. The prepared powder samples were single phase tetragonal crystal structure confirmed by the XRD studies, SEM images shows the inhomogeneous morphological nature. The EDS confirmed the existence of precursor elements in prepared samples. Under excitation with 381 nm, the CaLaGaO4:Tb3+ phosphors emission spectra shows characteristic emission peaks of Tb3+ ion at wavelengths of 490 nm, 543 nm, 580 nm and 624 nm and the calculated CIE values were indicates the green emission. The CaLaGaO4:Tb3+, Eu3+ co-doped phosphors stimulated under at a wavelength of 381 nm, the phosphors demonstrated emissions in green and red, which align with the characteristic wavelengths of Tb3+ and Eu3+, respectively. Moreover, the emission spectral data and fluorescence decay lifetimes evinced the energy transfer in CaLaGaO4:Tb3+, Eu3+ co-doped phosphors. Besides, at 0.5% doping concentration of Eu3+, the efficiency of energy transfer reached to 70.33% with 92.60% color purity. Furthermore, the mechanism of energy transfer from Tb3+ to Eu3+ in the CaLaGaO4 phosphors was established to occur through dipole-dipole interchange. The increment in Eu3+ ion concentration results in a color transition of prepared phosphors from green to yellow, and subsequently to red, attributed to the energy transfer mechanisms present. This phenomenon is ascribed due to the involvement of underlying energy transfer mechanisms. The outcomes demonstrated that the prepared CaLaGaO4:Tb3+, Eu3+ phosphors are might be suitable candidates for multicolor tunable phosphors, with potential applications in lighting and display technologies.

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