Mixed lead source precursors for producing light absorption layers of perovskite solar cells.

Beside the conventional perovskite precursors with lead halides as lead sources, non-halide lead sources provide additional tools for tuning the properties of perovskite layers, and lead acetate is a promising candidate for non-halide lead sources. In this work, we develop the perovskite precursor with a mixed non-halide lead source by partially replacing lead acetate with lead thiocyanate. Scanning electron microscopy and X-ray diffraction measurements indicate that lead thiocyanate additive can remarkably increase the size of perovskite grains and the crystallization of perovskite layers.

Localized incorporation of cesium ions to improve formamidinium lead iodide layers in perovskite solar cells.

For the perovskite solar cells with formamidinium lead iodide (FAPbI) as a light harvester, cesium ions (Cs) can be used to stabilize the perovskite crystal structure of FAPbI. However, the incorporation of Cs ions usually reduces the grain size and degrades the crystallization of FAPbI layers, and this is harmful to the photovoltaic performance of solar cells. In this work, we incorporate Cs ions into FAPbI layers using the interfacial doping method, which is different from the mixed solution doping method in previous reports.