Yb3+ and Yb3+/Er3+ doping for near-infrared emission and improved stability of CsPbCl3 nanocrystals

Abstract

Lead halide perovskite nanocrystals (NCs) exhibit excellent tunable emissions covering the entire visible spectral region, but they do not emit near-infrared (NIR) light. We synthesized rare earth element doped CsPbCl₃ NCs for NIR emission. The Yb³⁺ doped CsPbCl₃ NCs emitted strong 986 nm NIR light; the Yb³⁺/Er³⁺ co-doped CsPbCl₃ NCs emitted at 1533 nm. The total photoluminescence quantum yield (PL QY) of the CsPbCl₃ NCs changed from 5.0% to 127.8% upon incorporating 2.0% Yb³⁺, a factor of 25.6 times enhancement. The material's stability was tested under continuous ultraviolet (365 nm) irradiation. The doped CsPbCl₃ NCs exhibited a better stability than the undoped one. The PL intensity of the undoped CsPbCl₃ NCs dropped to 20% of the initial value in 27 h, while the doped one took 85 h.