摘要
Lanthanide luminescent materials with high quantum yield and thermal stability are of key importance for their practical application.Here we report crystal structures and luminescent properties of[Eu(pfbz)_(2)(phen)Cl](1)and[Tb(pfbz)2(phen)Cl](2)(pfbz=Pentafluorobenzoate).Single-crystal analysis reveals that both 1 and 2 crystallize in a polar space group of Cmc21.Investigation on their luminescent properties indicates that the solid-state quantum yields of 1 and 2 are 97.7%and 90.7%,respectively,while their efficiency of the sensitization process is as high as 100%,revealing that polar structures are more favorable to obtain high quantum yields.Thermogravimetric analysis reveals that both 1 and 2 can be stable up to 240℃.More importantly,temperature-dependent luminescent spectra of 1 indicate its luminescent intensity at 612 nm only decreased by 5%from room temperature to 373 K,whereas at 373 K,its luminescent intensity remains almost constant for 36 h.Considering that1 represents the highest quantum yield among known Eu-coordination polymers and its performance as the LED material is better than that of commercially widely used luminescent materials of(Sr,Ca)Al Si N3:Eu(630 nm)and(Sr,Ca)Al Si N3:Eu(640 nm),the present work provides an excellent substitute for commercial LED materials.
基金
supported by the National Natural Science Foundation of China(92161203,21721001,22022108)。
