Bi3+ and Eu3+ Co-Doped Cspbcl3 Pervoskite Quantum Dots with Efficient Controllable Blue Photoluminescence Via Energy Transfer

Halide perovskite quantum dots (QDs) are considered to be an outstanding optoelectronic and photonic materials. However, the heavy usage of toxic Pb element is still a serious problem, which can greatly hinder their practical application, and the problem needs to be solved. Herein, co-doping of different metal ions pairs in perovskite QDs host can solve this problem without affecting their optical properties. The highly monodisperse low-Pb content Cs(Pb x Bi 1-x )Cl 3 (x = 0.02-0.1) and Cs(Pb 0.95-y Bi 0.05 Eu y )Cl 3 (y = 0.05-0.50) perovskite QDs with cubic morphologies are successfully obtained by using the improved hot-injection method in the present work. The metal ions (Bi3+ and Eu3+)-doped do not alter the crystal structure and maintain the same lattice structure and crystallinity as their undoped CsPbCl 3 host, but that has an effect on the particle size owing to the difference in the ionic radius. Under the UV excitation wavelength of 380 nm, the perovskite QDs after being doped with metal ions all display their respective typical emission bands, including the band-edge emission of CsPbCl 3 host, the 3 P 1 → 1 S 0 transition of Bi 3+ , and the 5 D 0 → 7 F 2 transition of Eu 3+ . The relative intensities and the positions of their typical emission bands can be tuned though changing the metal ions doping content, meanwhile, the emission color of perovskite QDs can be readily tuned within a smaller wavelength range at the blue light area though varying the Bi 3+ or Eu 3+ doping content (the x or y values). The interesting spectroscopic behaviour benefits from the efficient energy transfers between the CsPbCl 3 host and doped metal ions, and the energy transfers are due to the differences in intrinsic energy levels of Bi 3+ or Eu 3+ . The metal-doped CsPbCl 3 perovskite QDs developed in this work can reduce the toxicity of perovskite QDs while improving the optical performance, which can provide a novel platform for the application in optoelectronic device applications