Green and high yield synthesis of CdTe@Hydrotalcite nanocrystals with enhanced photoluminescence stability toward white light emitting diodes

As a new type of luminescent material, quantum dots (QDs) with adjustable photoluminescence and narrow emission have attracted extensive attention in various fields. However, the large-scale production of QDs powders with high stability remains a key challenge, which greatly limits their wide applications. In this work, we synthesized highly stable QDs powders via a facile and simple co-precipitation method by embedding CdTe QDs into inorganic Mg₂Al(OH)₇ hydrotalcite matrix. This method shows distinct advantages of rapid separation of QDs powder through simple filtration, leading to a high yield of QDs powders and effectively avoiding heavy metal ions waste water. Compared with the parental CdTe QDs, the as-prepared CdTe@Mg₂Al(OH)₇ composites exhibit enhanced photoluminescence stability, longer photoluminescence decay lifetime, and better thermostability due to the protection of the Mg₂Al(OH)₇ hydrotalcite matrix. Based on the above excellent properties, we utilized the CdTe@Mg₂Al(OH)₇ powders as a red light conversion layer to prepare white light emitting diodes, which show high color-rendering properties with Commission Internationale de L'Eclairage (CIE) color coordinate of (0.3639, 0.3531), high color rendering index (CRI) value of 88, and color temperature (Tc) of 5112 K at 20 mA. This work offers an environmental friendly, low-cost and large-scale production route for high-performance QDs powders.