Benjamin S. Harrison

Near-infrared electroluminescence from conjugated polymer/lanthanide porphyrin blends

Near-infrared-emitting polymer light-emitting diodes (PLEDs) have been fabricated using blends of conjugated polymers and lanthanide tetraphenylporphyrin complexes. Host polymers include MEH–PPV and a bis-alkoxy-substituted poly(p-phenylene) (PPP–OR11), and the lanthanide complexes include Yb(TPP)acac and Er(TPP)acac (where TPP=5,10,15,20-tetraphenylporphyrin and acac=acetylacetonate). Electroluminescence (EL) is observed at 977 nm from devices fabricated using MEH–PPV or PPP–OR11 blended with Yb(TPP)acac, and EL is observed at 1560 nm from a device fabricated using a blend of MEH–PPV and Er(TPP)acac. Visible EL from the host polymers is strongly suppressed in all of the devices, however, in the device fabricated using the PPP–OR11 polymer blue emission from the host is completely quenched. Very efficient quenching of the EL from the host in the PPP–OR11 device is believed to occur due to efficient Forster energy transfer, which is facilitated by the excellent spectral overlap between the PPP–OR11 fluores...

Near-infrared organic light emitting diodes

Near-IR emitting organic light emitting diodes that contain an active material consisting of a blend of a poly(paraphenylene) and Ln-porphyrins are prepared and characterized.

Near-infrared display materials

With the increasing use of night vision goggles and night missions, new methods to display information in the infrared region is of interest. We have developed both inorganic and organic electroluminescent thin films which emit at wavelengths between 700 nm and 1.8 μm. These thin films have been incorporated into simple devices and the feasibility of a NIR flat panel display has been demonstrated. Both inorganic zinc sulfide and organic polymers doped with rare earth lanthanide ions have been demonstrated. The wavelength of emission can be varied by choosing the appropriate lanthanide ion, such as dysprosium, erbium, thulium or neodymium. Power densities of ~30 μW/cm2 have been achieved with these devices.