Color tunable Dy3+-doped Sr9Ga(PO4)7 phosphors for optical thermometric sensing materials

A series of Sr 9 Ga(PO 4 ) 7 : xDy 3+ (x = 0.00 ~ 0.18) phosphors were successfully synthesized via high-temperature solid-phase synthesis. The excitation and emission spectra of Sr 9 Ga(PO 4 ) 7 : xDy 3+ phosphor due to energy transfer from the Ga–O group to Dy 3+ can be detected by excitation at 259 and 482 nm. It is possible to adjust the luminous color from the blue light region to white light region through single-doping Dy 3+ in Sr 9 Ga(PO 4 ) 7 matrix, which is applicable for W-LEDs. Based on the temperature-dependent luminescence properties, Sr 9 Ga(PO 4 ) 7 : Dy 3+ phosphors has excellent thermal stability with absolute sensitivity (Sa) and relative sensitivity (Sr) at 598K of 0.018 K −1 and 0.87%K −1 , respectively by the fluorescence intensity ratio (FIR) technology. Therefore, the color tunable phosphor can be used as a thermal sensor in high-temperature environments.