Strongly confined blue-emitting CsPbI3 quantum dots synthesized using a green solvent: dihydrolevoglucosenone (Cyrene)

Abstract

All-inorganic, lead-based perovskite quantum dots (QDs) exhibit exceptional optoelectronic properties, positioning them as highly promising materials for a range of applications. However, their conventional synthesis typically relies on environmentally hazardous chemicals, including toxic solvents such as dimethylformamide (DMF), which pose serious health and ecological risks. This study addresses these concerns by employing dihydrolevoglucosenone (Cyrene), a bio-based and environmentally benign solvent, as a green alternative. CsPbI₃ QDs were synthesized via a facile, ligand-free reprecipitation method. Structural and morphological analyses using XRD, TEM, and Raman spectroscopy confirmed the formation of the γ-CsPbI₃ phase. By using ethanol and toluene as antisolvents, QDs with average particle sizes of 2.2 nm and 4.2 nm were obtained, respectively. Notably, a bright blue emission, not previously reported for CsPbI₃ QDs, was observed and is attributed to strong quantum confinement resulting from their ultra-small dimensions. A photoluminescence quantum yield (PLQY) of 70% was achieved. This study emphasizes the sustainable development of innovative materials with diverse applications, demonstrating the potential of eco-friendly approaches in advancing perovskite research.