Enhanced Stability and Luminous Performance for Structured Mn-Doped CsPbCl3 Quantum Dots

To improve the photoluminescence quantum yield (PL QY) and the environmental stability of the CsPbCl3 quantum dots (QDs), the Mn doping strategy has been applied first. The substitute of Mn2+ can reduce the toxicity of the lead element firstly, and then slightly enhance the stability of QDs. Increasing the nominal content of Mn, the longtime duration of the intrinsic excitation peak is significantly improved; and at a higher nominal content, a wide red emission by the d-d transition of Mn2+ is introduced, the overall PL QY of CsPbCl3 QDs increases to 54.32 %. Secondly, to further prevent the penetration of oxygen and water, the Mn-doped CsPbCl3@SiO2 nano-composite with a physical coating shell was synthesized by the hydrolysis of aminopropyltriethoxysilane. The investigation on the PL spectrum within hours shows that the relative peak intensity maintains 74 % of the initial intensity and the shift of peak position is also inhibited. Finally, the nano-composite materials were fabricated into white light-emitting devices (WLED), under the illumination of a commercial GaN chip, the device shows a good Commission Internationale de lEclairage (CIE) color coordination of (0.31,0.35). As a result, the obtained Mn-doped CsPbCl3@SiO2 QDs have excellent optical properties and good stability under aqueous and polar solvent environments. Therefore, this doping and coating method could pave the way for future applications in illumination and display fields.