Novel single-component CaLaAlO4:Tb3+, Eu3+ phosphor for white light-emission

Tb3+/Eu3+ single and co-doped CaLaAlO4 (CLA) phosphors were successfully prepared by solution combustion route. The luminescence properties of Tb3+ and Eu3+, and the energy transfer (ET) from Tb3+ to Eu3+ were investigated. Microstructures are analyzed by X-ray diffraction and high-resolution scanning electron microscope (SEM) experiments. The sample shows single tetragonal structure. Under the excitation of 260 nm, CLA:Tb3+, Eu3+ phosphors exhibited green emission corresponding to the f-f transition of Tb3+ ions and red emission bands corresponding to the f-f transition of Eu3+ ions, respectively. With appropriate tuning of the Tb3+/Eu3+ ratio, tunable photoluminescence emission from blue-green to yellow and red is obtained in Tb3+ and Eu3+ co-doped CLA phosphors and emission spectrum covers the entire visible light region with comparable intensity, resulting in white emission. Moreover, the CLA:0.01 Tb3+, 0.02Eu3+ assembly have Commission International del'Eclairage (CIE) chromaticity coordinates x = 0.3277 and y = 0.3370, which is close to the standard white-light color (x = 0.333 and y = 0.333), demonstrating its great potentials as single-component (single-phase) phosphors for white light emission. The maximum ET efficiency is found to be 63.77% for CLA:0.01 Tb3+, 0.03Eu3+ phosphor.