High sensitivity of whitlockite-type phosphor toward optical thermometric

Whitlockite-type structure phosphors have been widely studied due to their adjustable chemical composition and abundant crystal location. Whitlockite-type phosphors can be doped with rare earth elements to achieve the emission of warm white light. White light-emitting diodes (w-LEDs) have become increasingly popular and play a significant role in many applications, such as Biosensing and fluorescent labeling. In this work, The Ca2.6K0.2La0.2(PO4)2(CKLP) whitlockite-type phosphors co-doped with Dy3+ and Sm3+ were entered via a hightemperature solid-phase reaction. Their crystal structure, luminescence characteristics, and temperature sensitivity were explored in detail. Through doping Dy3+ and Sm3+, can obtain white light and warm white light. As the concentration of Sm3+ increased, their lifetime decreased from 0.483 ms to 0.059 ms, confirming interionic energy transfer in the host. The CKLP: 0.06Dy3+, 0.06Sm3+ phosphor prepared by Fluorescence Intensity Ratio (FIR) technology has suitable temperature sensing performance. Its relative sensitivity (Sr) and complete sensitivity (Sa) are high up to 4.48 x 10-3 k-1 and 1.021%K-1 at 298 K. The results show that CKLP: Dy3+ and Sm3+ phosphors used in w-LEDs and display devices will present excellent application potential in new optical thermometry.