fig4

Figure 4. (A) Schematic illustration of the LSC integrated with a silicon solar cell; (B) Photograph of an LSC based on Yb³⁺-doped CsPbCl₃ NCs under sunlight (dimension: 5 cm × 5 cm × 0.3 cm); (C) Photograph of the LSC captured by a near-infrared camera under ultraviolet light (365 nm) illumination. Photographs in Figure 4B and C were taken by the authors; (D) PL spectra of the CdCl₂-treated Yb³⁺:CsPbCl₃ NC solution and the corresponding LSC; (E and F) Internal optical efficiency (E) and external optical efficiency (F) of Yb³⁺:CsPbCl₃ NC-LSCs before and after CdCl₂ post-treatment. Error bars in (E and F) represent the standard deviation from three independently fabricated LSCs; (G) J-V curves of the silicon photovoltaic cells integrated with untreated and CdCl₂-treated NC-LSCs. LSCs: Luminescent solar concentrators; NCs: nanocrystals; J-V: current density-voltage; PL: photoluminescence; BG: band gap.