Luminescent Solar Concentrators Based on Lanthanide Bimetallic Red-Emitting Metal-Organic Framework

Luminescent solar concentrators (LSCs) are large-area, high-efficiency solar energy-harvesting devices with considerable potential in building-integrated photovoltaics. Their performance is dominantly governed by the luminescent materials, which determine the light-harvesting efficiency, spectral conversion capability, and long-term operational stability of the devices. As important luminescent materials, metal-organic frameworks (MOFs) have advantages for LSC applications, including high luminescent efficiency, excellent stability, low environmental impact, and facile synthesis. Nevertheless, despite these favorable characteristics, the exploration of MOF-based luminescent materials in LSC devices remains relatively limited. In this work, a red-emitting MOF, designated as SCU-UEu-2, was synthesized with high reaction yield and good feasibility for large-scale production. Compared with Eu-based MOFs, SCU-UEu-2 shows a broader excitation range, while in contrast to quantum dots, it exhibits a narrower emission bandwidth. Moreover, the minimal spectral overlap between its absorption and emission effectively suppresses reabsorption energy losses, thereby improving LSC efficiency. The photoluminescent quantum yield (PLQY) of the SCU-UEu-2 reaches 90.28%. As a proof of concept, an LSC device incorporating SCU-UEu-2 was fabricated and systematically evaluated. Under simulated sunlight illumination (100 mW·cm^-2), the device achieved a maximum optical conversion efficiency (η_opt) of 9.9%, demonstrating strong potential of MOF-based luminescent materials for high-performance LSC applications.