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 °C) to produce CuInSe₂ nanocrystals with size-tunable photoluminescence spectra ranging from ∼600 to ∼850 nm. Two-dimensional photoluminescence excitation-emission maps are reported for the CuInSe ₂ nanocrystals, highlighting the size-tunable excitonic features. Type I heterostructured CuInSe₂/ZnS nanocrystals are prepared and purified. They are found to have absolute photoluminescence quantum yields up 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.