Light-emitting devices having an emitting layer containing a light-emitting organic or organometallic material and a
nanostructure, the
nanostructure having strong local electric fields at visible electromagnetic wavelengths that spectrally and spatially overlap with the light-emitting material. The spectral and spatial overlap of the electric fields of the
nanostructure with the light emitting material uses high LDOS provided by the nanostructures to enable excited triplet
electronic states in the material to emit light faster than without the nanostructure. This faster
light emission from triplet-excited states leads to more stable emission from the light emitting material because it prevents buildup of triplet-excited states, which ordinarily can lead to
quenching of
light emission from the light emitting material. Among the many different possibilities contemplated, the nanostructure may advantageously be made of a
dielectric material or a plasmonic
metal material, such as SiO2, TiO2, ZnO, Al or Ag. It is further contemplated that the light-emitting material be capable of exhibiting at least one of
phosphorescence or thermally-assisted delayed
fluorescence. Many light-emitting materials, including
blue light emitters, may be utilized, and may also be doped into a
host material. It is still further contemplated that the nanostructure may be a nanoantenna, a
nanoparticle, such as a sphere or rod, a
nanoporous film, or an imprinted
grating, and the nanostructure may be on either side of the light-emitting material, or may be surrounded by or embedded in the
host material. The light-emitting device may also advantageously include other
layers, including but not limited a
hole transport layer, a hole
blocking layer, an
electron transport layer, a
hole injection layer, or an
electron injection layer. Further, the device may also be configured for use in various applications, including but not limited to bioimaging,
photochemistry, and single molecule
spectroscopy.