(101a) Quantum Dot Nanocrystals for Efficient Solid-State Lighting

White light emitting diodes (WLEDs) based solid state lighting is considered to be a promising energy-efficient light source to address the ever-growing demands for energy and the concerns of climate change. Semiconductor nanocrystals (such as quantum dots) contribute significantly toward WLEDs development to potentially replace the currently used incandescent and fluorescent lamps. The most popularly studied cadmium-containing quantum dots raise toxicity concerns to the environment and human beings. Thus, we introduce a type of WLEDs, which are based on the nontoxic and non-rare-earth nanocrystals (such as ZnO and CuInS₂). Generally, ZnO nanocrystals exhibit the blue-emitting band gap emission. By adjusting reaction conditions, the blue-emitting ZnO nanocrystals could be triggered with a large amount of green trap emission. After integrating the trap-contained ZnO nanocrystals with the red-emitting CuInS₂ nanocrystals, white emission could be eventually produced. We have also explored direct white-light emission from magic-sized quantum dots. For the fabrication of our WLEDs, these nanocrystals were directly deposited onto a glass substrate and then thermally annealed, or first dispersed in polymer and afterwards transferred onto UV-pumped LEDs.