NEBULAE · Eco-friendly ytterbium-doped perovskite nanocrystals embedded in glasses for solar cells

Quantum cutting down-conversion materials have emerged as a novel approach to increase solar cell efficiency by reshaping the solar spectrum. Efforts worldwide have focused on Yb-doped lead halide perovskite nanocrystals (PNCs) due to their highly efficient near-infrared (NIR) photoluminescence (PL) that matches the bandgap of the commonly used photovoltaic materials. However, two major challenges limit their commercialization: 1) the high toxicity of lead (Pb), 2) the instability of PNCs against moisture. Therefore, there is a need to develop Yb-doped Pb-free PNCs and embed them in dense structures like glass to increase their chemical stability over time. To this end, the interdisciplinary NEBULAE project aims to develop new fluorophosphate (FP) glass-ceramics (GCs) that contain Yb-doped Pb-free PNCs. It will be the first to report not only Pb-free PNCs in FP glass but also Yb-doped perovskite FP GCs for solar cells. Thus, 1) Yb-doped FP glasses will be synthesized using the melt-quenching method and characterized by a complex of spectroscopic methods to study the composition-property relation. 2) Nucleation and growth will be investigated, and heat treatment will be conducted to obtain transparent GCs with enhanced NIR PL, in which Yb-doped Pb-free PNCs are embedded in the volume of the glass. 3) The GCs will be tested in a solar cell to demonstrate proof-of-concept improvement in cell performance. NEBULAE is based on the PIs expertise in optics, the supervisors in glass science, and the co-supervisors in solar cells, ensuring the achievement of the research goals, dissemination, and exploitation of the results. The training/research activities will equip the PI with the skills needed to apply to ERC Starting Grant and/or obtain a tenure track in the EU, which will allow the PI to launch his own research group. NEBULAE contributes to UN Sustainable Development Goals and EU Green Deal by reducing the use of toxic elements and promoting clean energy.