Efficient and Stable Blue CsPbBr₃ Perovskite Nanocrystals through Cd-Ion Thermal Doping of CdS Quantum Dots

Blue-light halide perovskite nanocrystals (NCs) have faced significant limitations in optoelectronic applications due to challenges in size control, photoluminescent efficiency, and stability. This work introduces a novel thermal doping method by utilizing unique CdS quantum dots (QD) as a Cd source to convert green-light CsPbBr₃ NCs to blue-light perovskite NCs. The dynamic dissociation of CdS QDs at 120 °C ensures a stable supply of Cd ions during the doping process. The doped cubic perovskite NCs, with an increased size (∼20 nm), exhibit efficient blue-light emission. Furthermore, the doped NCs demonstrate exceptional air and thermal stability in solid films, attributed to lattice contraction and reduced surface energy, effectively addressing common issues associated with blue-emitting perovskite NCs. This method provides a robust pathway for producing efficient and stable blue-light perovskite NCs, offering promising potential for enhancing the performance of blue-light perovskite NC-based light-emitting diode devices.