Colloidal CuInSe2 Nanocrystals in the Quantum Confinement Regime: Synthesis, Optical Properties, and Electroluminescence

Photoluminescent, near-stoichiometric colloidal CuInSe2 nanocrystals are synthesized in large batches and with good colloidal quality. An organometallic method is used with a moderate reaction temperature (<= 200 degrees C) to produce CuInSe2 nanocrystals with size-tunable photoluminescence spectra ranging from similar to 600 to similar to 850 nm. Two-dimensional photoluminescence excitation-emission maps are reported for the CuInSe2 nanocrystals, highlighting the size-tunable excitonic features. Type I heterostructured CuInSe2/ZnS crystals are are prepared and purified. They are found to have absolute photoluminescence quantum yields up to similar to 26%. The potential to use CuInSe2/ZnS core/shell nanocrystals as a potential low toxicity active layer in light-emitting diodes is demonstrated by fabricating electroluminescent devices.