Directionally Emissive Luminescent Solar Concentrators Enabled by Electrically Aligned Quantum Rods within a Polymer...

Luminescent solar concentrators (LSCs) are highly transparent, cost-effective photovoltaic devices that convert sunlight into fluorescence, which is then concentrated on peripheral solar cells via total internal reflection (TIR). In this Letter, we systematically analyzed the influence of directional emission on the efficiency of LSCs, revealing that directional emission not only enhances TIR efficiency but also mitigates light propagation losses. To validate this, we utilized highly bright and polarized emitting CdSe/CdZnS quantum rods (QRs) as the emitter. By developing an electrically aligned photopolymerization technique, we successfully induced and fixed the orientation of the QRs within a polymer matrix, thereby preventing the aggregation-induced quenching. Further characterization demonstrated a 1.23-fold efficiency improvement for the directionally emitting LSC device compared to its isotropic counterpart. Ultimately, the 3.5×3.5×0.85  cm^{3} laminated-glass device achieved an extremely high power conversion efficiency of ∼4.92%. By adjusting QRs concentration, a light utilization efficiency of ∼2.39% with over 60% transmittance was obtained, rivaling state-of-the-art transparent photovoltaic devices.