Highly efficient near-infrared hybrid organic-inorganic nanocrystal electroluminescence device

We report the use of PbS nanocrystals within a hybrid device that emits 1.2 mu m electroluminescence with an external quantum efficiency of 1.15% corresponding to an internal quantum efficiency of similar to 5%-12% thus demonstrating a viable, low-cost, highly efficient near infrared organic electroluminescent device. Direct generation of the excited state on the nanocrystal result in eliminating competing processes that have previously led to the low reported efficiencies in near-infrared light emitting devices. Furthermore, the emission wavelength can be tuned to cover a wide range of wavelengths including the 1.3-1.5 mu m region without significant change of the efficiency. (c) 2008 American Institute of Physics.