A novel and tunable upconversion luminescent material GdPO4: Yb3+, Ln3+ (Ln = Er, Tm, Ho)

A novel and tunable upconversion luminescent material GdPO4: Yb3+, Ln3+ (Ln = Er, Ho, Tm) has been synthesized by conventional solid-state reaction method. Simultaneous red, green and blue (RGB) emissions were obtained after excitation at 980 nm. Color emission was tuned from multicolor to white light with color coordinate (0.328, 0.327) matching very well with the white reference (0.333, 0.333). Changes in color emissions were obtained by varying the intensity ratios between RGB bands that were strongly concentration dependent because of the interaction of co-dopants. The color tunability, high quality of white light and high intensity of the emitted signal make these upconversion (UC) phosphors excellent candidates for applications in solid-state lighting.