We report 890 nm luminescence from a neodymium-doped polymer light-emitting diode. The active layer is a blend of poly(dioctylfluorene-co-benzothiadiazole), F8BT, and a lissamine-functionalized terphenyl-based neodymium complex. We detect electroluminescence from both the lissamine (580 nm) and the Nd3+ complex (890 nm). By comparison with lissamine-free devices we show that the lissamine is crucial to infrared emission. The neodymium/lissamine luminescence intensity ratio is higher under electrical excitation than under optical excitation, showing that more triplets reach Nd3+ under electrical excitation. High turn-on voltages provide a clear indication for charge trapping onto the lissamine, and we consider direct triplet formation on the lissamine to be competing efficiently with respect to slower Dexter-type triplet transfer from the F8BT to the lissamine.

Appl. Phys. Lett.
Photonic Materials

Slooff, L. H., Polman, A., Cacialli, F., Friend, R., Hebbink, G. A., van Veggel, F. C. J. M., & Reinhoudt, D. N. (2001). Near-infrared electroluminescence of polymer light-emitting diodes doped with a lissamine-sensitized Nd3+ complex. Appl. Phys. Lett., 78, 2122–2124.