Highly Efficient Tandem Luminescent Solar Concentrators with a Stokes Shift Exceeding 100 nm Based on Giant InP Quantum Dots

Indium phosphide (InP) colloidal quantum dots (QDs) show promising optical properties but face self-absorption losses in luminescent solar concentrators (LSCs). Mn²⁺ doping addresses this issue. Halide ions in precursors critically influence doping efficiency: iodide's weaker electronegativity reduces binding energy with surface cations, promoting thermal desorption during synthesis and enhancing shell growth and Mn²⁺ incorporation. Using iodide precursors, Mn:InP/ZnS giant QDs (14.3 nm) are synthesized with a Stokes shift of 101 nm and a PLQY of 83%, owing to reduced lattice mismatch. These QDs retain 80% initial emission after 1000 h under aging conditions (60 °C, 90% humidity, blue light), demonstrating exceptional stability. The resulting LSCs achieve an external optical efficiency of 3.62% and a power conversion efficiency of 3.06% under simulated sunlight (100 mW/cm²), representing state-of-the-art performance for InP-based LSCs and highlighting their potential for eco-friendly LSCs technologies.