Fig. 5.

Upconversion lifetime tuning in nanoparticle (NP)-sensitized CsPbX₃ perovskite quantum dots (PeQDs). a Upconversion luminescence (UCL) decays from the upconverted excitons in NP-sensitized CsPbCl₃, CsPbBr₃, and CsPbI₃ PeQDs (0.5 mol% Tm³⁺) by monitoring their emissions at 410, 520, and 700 nm, respectively, under 980 nm excitation. b UCL lifetimes of ¹I₆, ¹D₂, ¹G₄, and ³H₄ of Tm³⁺ in LiYbF₄:x%Tm³⁺@LiYF₄ core/shell NPs as a function of the Tm³⁺ concentration. c UCL decays from the upconverted excitons in NP-sensitized CsPbBr₃ PeQDs with varying Tm³⁺ concentration in the NPs. d UCL lifetimes of CsPbCl₃, CsPbBr₃, and CsPbI₃ PeQDs as a function of the Tm³⁺ concentration