Cu-doped nanocrystal carbon dots for integrated fabrication of ultrabright luminescent solar concentrators

Carbon dots (CDs) are promising fluorophores for optoelectronic devices. Yet, achieving CDs with high solid-state photoluminescence quantum yields (PLQYs) remains a significant challenge. The development of metal-doped carbon dots (CDs) to effectively modulate their electronic properties and surface chemical reactivities is still in its early stages. This work introduces copper-doping to CDs (Cu-CDs) luminescent material to modify the optoelectronic properties of CDs. The as-synthesized CDs show a Stokes shift of ≈0.67 eV and high PLQYs of 62 %. The Cu-CDs show the highest power conversion efficiency of 2.36 % compared to CDs (2.04 %) with a Stokes shift of 0.71 eV. These findings demonstrate the possibility of tuning optical properties into CDs via metal doping, obtaining eco-friendly, high-efficiency LSCs through scalable production techniques, paving the way to the lab-to-fab transition of this kind of device. Our results demonstrate that dual-emission Cu-CDs with strong solid-state fluorescence are promising candidates as luminophores in efficient photovoltaic devices.