Lanthanide 9-anthracenate: solution processable emitters for efficient purely NIR emitting host-free OLEDs

Searching for new NIR emitting materials, lanthanide 9-anthracenates Ln( ant ) 3 were synthesized and thoroughly characterized. Ytterbium 9-anthracenate Yb( ant ) 3 , that demonstrated the highest NIR luminescence efficiency, was successfully used as an emission layer of a host-free OLED and its electroluminescence quantum efficiency, corresponding to the sole band at 1000 nm, reached 0.21%. This performance could be achieved due to the high quantum yield of Yb( ant ) 3 , which reached 1.5% and was increased up to 2.5% by partial Yb 3+ substitution with Lu 3+ , as well as its high electron mobility due to the extended stacking in its crystal structure. The first gadolinium-based PHOLED was prepared based on Gd( ant ) 3 .