Water triggered interfacial synthesis of highly luminescent CsPbX3:Mn2+ quantum dots from nonluminescent quantum dots

Currently, lead halide perovskite quantum dots (PeQDs) have attracted great attention due to their spectacular photophysical properties. However, the toxicity of Pb2+ heavy metal ions in CsPbX3 PeQDs limits their practical applications. Herein, a facile post-treatment doping method is proposed, which enables the preparation of highly luminescent low-toxic CsPbX3:Mn2+ PeQDs from nonluminescent Cs4PbX6 PeQDs at water interface. The monodispersed CsPbX3:Mn2+ PeQDs exhibit excellent photophysical properties, including high photoluminescence quantum yield up to 87%. The reaction process and doping mechanism are deeply explored through in-situ monitoring. By simply adjusting the halide composition of the original Cs4PbX6 PeQDs or Mn doping concentration, a series of CsPbX3:Mn2+ PeQDs with adjustable emission could be obtained. Further, the CsPbX3:Mn2+ Q-LED was fabricated and exhibited excellent orange light with the color coordinates of (0.564, 0.399), correlated color temperature (CCT) of 1,918 K, and luminous efficiency (LE) of 24 lm/W, which illustrate the great promise in light emitting diode (LED) applications. This work not only provides a facile method for the preparation of highly luminescent low-toxic CsPbX3:Mn2+ PeQDs, but also provides insights into the mechanism of doping process.