Strongly Emissive Perovskite Nanocrystal Inks for High Voltage Solar Cells

Lead halide perovskite semiconductors have recently gained wide interest following their successful embodiment in solid-state photovoltaic devices with impressive power conversion efficiencies, while offering a relatively simple and low cost processability. While the primary optoelectronic properties of these materials have already met the requirement for high efficiency optoelectronic technologies, industrial up-scale requires more robust processing methods and less toxic solvents than have been commonly used so successfully on the lab-scale. Here, we report a fast, room-temperature synthesis of inks based on CsPbBr₃ perovskite nanocrystals using short, low boiling-point ligands and environmentally friendly solvents. Requiring no lengthy post-synthesis treatments, the inks are directly used to fabricate films of high optoelectronic quality, exhibiting photoluminescence quantum yields higher than 30% and an amplified spontaneous emission threshold as low as 1.5 mJ/cm². Finally, we demonstrate the fabrication of a perovskite nanocrystal-based solar cells, with open circuit voltages as high as 1.5 V.