Fig. 5: Optical characteristics of QC-LC.

Absorption spectra (a), emission spectra (b), and PLQYs (c) of undoped, Cr³⁺, Cr³⁺ / Yb³⁺ / Er³⁺, and Cr³⁺ / Ce³⁺ / Yb³⁺ / Er³⁺ doped CsPbCl₃ PQDs. d Energy level diagram of Cr³⁺ / Ce³⁺ / Yb³⁺ / Er³⁺ doped CsPbCl₃ PQDs. e The emission spectra of QC–LC using an integrating sphere method. To accuracy obtained the face emission spectra of QC–LC, the black tapes with high light absorption was used to the edges of QC–LC. The inset is the picture of QC-LC. f Normalized PL intensity of QC–LC and Cr³⁺ / Ce³⁺ / Yb³⁺ / Er³⁺ doped CsPbCl₃ PQDs films as a function of storage time