Cost-efficient, effect of low-quality pbi₂ purification to enhance performances of perovskite quantum dots and perovskite solar cells

In modern society, high-quality material development and a large stable supply are key to perform frontier research and development. However, there are negative issues to address to utilize high-quality resources with a large stable supply for research, such as economic accessibility, commer-cialization, and so on. One of the cutting-edge research fields, perovskite-related research, usually requires high-quality chemicals with outstanding purity (>99%). We developed an economically feasible PbI₂ precursor with around 1/20 cost-down for perovskite/perovskite quantum dots through recrystallization and/or hydrothermal purification. Following the methodology, the quantum dots from both as-prepared and purified PbI₂ demonstrated identical photophysical properties, with a photoluminescence quantum yield (PLQY) of 52.61% using the purified PbI₂ vs. 45.83% PLQY using commercial PbI₂. The role of hydrothermal energy was also checked against the problematic PbI_2, and we checked whether the hydrothermal energy could contribute to the hindrance of undesired particle formation in the precursor solution, which enables them to form enlarged grain size from 179 ± 80 to 255 ± 130 nm for higher photoconversion efficiency of perovskite solar cells from 14.77 ± 1.82% to 15.18 ± 1.92%.