Amplifying Photoluminescence of Lanthanide-Doped Nanoparticles by Iridium Phosphonate Complex

Amplifying the photoluminescence of lanthanide-doped
nanoparticles
by antenna materials can bridge the gap in properties between pristine
nanoparticles and those required by practical applications. However,
high-performance antennas with ideal stability are rather few. Here,
we report a new type of iridium (Ir)-based phosphonate complex as
an antenna to amplify the near-infrared luminescence of lanthanide-doped
nanoparticles. Unlike conventional antennas, the Ir complex, with
a quasi-spherical structure and pendent phosphonic groups, can resist
the aggregation-caused quenching and firmly anchor on nanoparticles.
Near-infrared luminescence of lanthanide-doped nanoparticles can be
stably amplified up to 130 times by the complex, which should be due
to short-range energy transfer from the triplet state of the complex
to lanthanide ions. These findings may pave a new fundamental way
to amplify the luminescence of lanthanide-doped nanoparticles and
promote applications of the nanoparticles.