Intense near-infrared quantum cutting emissions in LaF3:Sm3+ nanocrystals.

In this letter, visible to near-infrared (NIR) quantum cutting (QC) luminescence of -20 nm LaF3:Sm3+ (0.2-1 mol%) nanocrystals (NCs) was first studied. A number of novel NIR QC emissions (850-2000 nm) were distinguished. The results show that the QC emission lines and populating channels depend strongly on Sm3+ concentration due to the cross relaxation processes. The overall QC efficiency is as high as -193% in LaF3:Sm3+ (0.4 mol%) NCs, which shows that NIR QC of Sm3+ is of great significance for enhancing the efficiency of solar cells.