Highly Efficient Luminescent Solar Concentrators Based on Composition-Tunable ZnCuInSe/ZnSe Quantum Dots

Luminescent solar concentrators (LSCs) are promising, cost-effective, large-area solar collectors for building-integrated photovoltaics (BIPVs). However, most of the recently reported efficient LSCs contain heavy metal ions, such as Pb or Cd, which limits their potential practical applications. Here we demonstrated eco-friendly ZnCuInSe/ZnSe (ZCISe/ZnSe) core/shell quantum dots (QDs) and integrated them into a poly(methyl methacrylate) (PMMA) polymer matrix to fabricate LSCs (10 × 10 × 0.5 cm³). The optical properties were regulated by tuning the Zn/Cu molar ratio. Notably, with increasing Zn content, the absorption/emission spectra of these QDs showed first a red-shift and then a blue-shift. As a proof-of-concept, the as-fabricated LSC based on the ZCISe/ZnSe QDs with a Zn/Cu molar ratio of 2/3 exhibited an optimal optical efficiency of 3.38% under natural sunlight illumination (66 mW/cm²) and an external optical efficiency of 3.59 ± 0.12% under natural sunlight illumination (60–70 mW/cm²). Our results highlight that these eco-friendly ZCISe/ZnSe core/shell QDs with composition-dependent optical properties hold great potential for the development of future practical optoelectronic devices.