Luminescent materials often suffer from thermal quenching(TQ),limiting the continuation of their applications under high temperatures up to 473 K.The formation of defect levels could suppress TQ,but rational synthesis...Luminescent materials often suffer from thermal quenching(TQ),limiting the continuation of their applications under high temperatures up to 473 K.The formation of defect levels could suppress TQ,but rational synthesis and deep understanding of multiple defects-regulated luminescent materials working in such a wide temperature range still remain challenging.Here,we prepare a negative thermal quenching(NTQ)phosphor LiTaO_(3)∶Tb^(3+)by introducing gradient defects V_(Ta)^(5−),Tb_(Li)^(2+),and(V_(Ta)Tb_(Li))^(3−)as identified by advanced experimental and theoretical studies.Its photoluminescence significantly becomes intense with rising temperatures and then slowly increases at 373 to 473 K.The mechanism studies reveal that gradient defects with varied trapping depths could act as energy buffer layers to effectively capture the carriers.Under thermal disturbance,the stored carriers could successively migrate to the activators in consecutive and wide temperature zones,compensating for TQ to enhance luminescence emission.This study initiates the synthesis of multi-defect NTQ phosphors for temperature-dependent applications.展开更多
基金the National Key Research and Development Program of China(Grant No.2018YFB0704103)the Natural Science Foundation of Shanghai(Grant Nos.22ZR1472100 and 20ZR1465900)+3 种基金the National Natural Science Foundation of China(Grant Nos.92163117 and 62175210)the State Key Laboratory of ASIC&System(Grant No.2020KF002)the Innovation Project of Shanghai Institute of Ceramics(Grant No.E21ZC1770G)L.L.thanks the Taiwan Light Source for technical support.J.W.thanks the Program of Shanghai Academic Research Leader(Grant No.20XD1424300)for financial support.The authors thank Professor Zhijun Zhang for providing valuable assistance in stress luminescence testing.
文摘Luminescent materials often suffer from thermal quenching(TQ),limiting the continuation of their applications under high temperatures up to 473 K.The formation of defect levels could suppress TQ,but rational synthesis and deep understanding of multiple defects-regulated luminescent materials working in such a wide temperature range still remain challenging.Here,we prepare a negative thermal quenching(NTQ)phosphor LiTaO_(3)∶Tb^(3+)by introducing gradient defects V_(Ta)^(5−),Tb_(Li)^(2+),and(V_(Ta)Tb_(Li))^(3−)as identified by advanced experimental and theoretical studies.Its photoluminescence significantly becomes intense with rising temperatures and then slowly increases at 373 to 473 K.The mechanism studies reveal that gradient defects with varied trapping depths could act as energy buffer layers to effectively capture the carriers.Under thermal disturbance,the stored carriers could successively migrate to the activators in consecutive and wide temperature zones,compensating for TQ to enhance luminescence emission.This study initiates the synthesis of multi-defect NTQ phosphors for temperature-dependent applications.
