The Impact of Precursor Ratio on the Synthetic Production, Surface Chemistry, and Photovoltaic Performance of CsPbI3 Perovskite Quantum Dots

Lead‐halide perovskite quantum dots (QDs) have attracted substantial attention due to their great potential in solution‐processed optoelectronic applications. The current synthetic method mostly relies on the binary‐precursor strategy, which significantly restricts the reaction yield and elemental regulation, leading to extremely high material cost. Herein, a more versatile ternary‐precursor method to investigate the effect of the precursor ratios on the synthetic production, surface chemistry, and photovoltaic performance of CsPbI 3 QDs is explored. It is revealed that a decreased Pb/Cs feeding ratio can largely increase the reaction yield, whereas a reduced Pb/I ratio can improve the surface termination and optical properties of the resultaning CsPbI 3 QDs. After rational tuning of the synthetic protocol, the reaction yield can be improved more than 7.5 times and the material cost can be reduced from 303 $ g −1 to as low as 42 $ g −1 compared to the conventional binary‐precursor method. In addition, the photovoltaic device using these QDs exhibits an efficiency close to the reported state‐of‐the‐art ones. It is believed that this scalable and low‐cost preparation of CsPbI 3 QDs provides new insight into the future commercialization of perovskite QDs‐based optoelectronics.