Li2CaSi2N4:Sm3+: A nitride-based red phosphor with excellent temperature sensitivity and cathodoluminescence for temperature sensor and FED

Abstract

Temperature sensor and field emission displays (FED) are the intensive topics for Sm3+ activated red phosphor. In this study, a novel lithium nitride red phosphor Li2CaSi2N4:Sm3+ was successfully prepared by solid phase method. The photoluminescence and cathodoluminescence performances were systematically studied to explore the possibility in FED and temperature sensor applications. The results indicate that the Li2CaSi2N4:Sm3+ phosphor features intense red emission under the UV light and cathode ray excitations. The phosphor also has a long red afterglow with an afterglow time of 12.7 min. Most importantly, Li2CaSi2N4:Sm3+ exhibits excellent temperature sensitivity with the relative sensitivity of 4.8% K−1 @473 K, which is higher than other temperature sensor materials. The thermal quenching mechanism was proposed based on a configurational-coordinate model. Moreover, excellent cathode ray saturation and aging resistance were observed in Li2CaSi2N4:Sm3+. The results indicate that Li2CaSi2N4:Sm3+ is a potential temperature sensor and FED materials.