Bright White-Light Emitting Manganese and Copper Co-Doped ZnSe Quantum Dots

摘要

White-light emission (WLE) from semiconductor nanostructures is presently a research area of intense interest, especially where the primary objective is to replace conventional light sources in order to minimize energy costs and therefore global energy consumption for lighting. Presently the general methods to achieve white-light emission are either by coating a yellow phosphor or by combining green and red phosphors on a background consisting of a blue-light emitting diode (LED) or by employing nanocrystals (NCs) of the three primary colors (red, green, blue) using multilayer structures in LEDs. However, when one simply mixes these nanocrystal quantum dots (QDs) of different colors together to generate white light, the efficiencies are often observed to decrease due to the re-absorption of light and subsequent undesired energy transfer (ET). This may lead to undesirable changes in the chromaticity coordinates and photometric performance due to the different relative temporal stabilities of the components. Hence the use of a single-emitting component offers many advantages over multiple component systems for white-light emitting sources such as LEDs, amongst which are: greater reproducibility, low cost preparation, ease of modification, and simpler fabrication processes. Therefore, it is of great importance for many applications to find high-quality single source white-light emitters through low-cost chemical synthesis approaches that will allow the production of white light while meeting the needs of industry, such as satisfactory Commission International d'Eclairage (CIE) coordinates.