CsPbCl3:Yb3+/Mn2+ Perovskite Nanocrystals Fabricated by Solvent-assisted Mechanochemical Synthesis for Luminescent Down-conversion in Photovoltaic Devices

Optimal solar energy harvesting in silicon photovoltaics (Si-PV) relies significantly on effective light management strategies such as texturing and anti-reflective coatings. Nevertheless, external quantum efficiency is low in the blue spectral region due to high parasitic absorption and high surface recombination rates limiting the overall performance of Si-PV systems. Luminescent down-converting layers offer a promising solution by absorbing high-energy photons and re-emitting them as lower-energy photons that align with the high-EQE region of the semiconductor. In this work, we demonstrate an accessible solvent-assisted mechanochemical synthesis method to synthesize CsPbCl3:Yb3+/Mn2+ nanocrystals, a promising luminescent down-converting material. By co-doping the perovskite matrix with Mn2+ and Yb3+ ions, high-energy UV and blue photons are absorbed and re-emitted as red and near-infrared photons. Structural (x-ray diffraction) and optical (absorbance, photoluminescence) analyses confirm the successful synthesis and desired optical properties of these nanocrystals. Total photoluminescence quantum yields of 44% have so far been achieved, with significant potential for further improvement. The straightforward synthesis method presented here lowers the barriers to producing high-performance spectral conversion materials, enabling broader adoption in research and paving the way for eventual integration into Si-PV devices.