Realize the Counterbalance between Sustainability and Photovoltaic Performance of Organometal Halide Perovskite Solar Cell

The containing toxic Pb in perovskite solar cells may obstacle the pace of its further progress. Based on appropriated ionic radius and stable valence electron, barium is the most suitable alkaline earth element for lead substitution in perovskite material. To enhance the tolerance of lead substitution in perovskite material, a bulky cation of phenylethylammonium (PEA⁺) was induced into the perovskite to serve as A-site cation. The bulky size and dipolar intrinsic properties render it to simultaneously induce a quasi 2D/3D structure (n>40) and to passivated the ionic defects in such perovskite material. Herein, we induced PEA⁺ into perovskite to enlarge the limitation of barium substituted ratio. In addition, the optoelectronic properties and morphology were also improved as 1 mol.% of PEA adopted into the lead reduced perovskite. Taking these advantage, the ratio of barium substitution in dual cation perovskite system can reach to 10 at.% and the corresponding photovoltaic performance can attain 19.1% in a n-i-p configuration. These results shed the light on how to delineate a framework for lead reduction in organometal halide perovskite solar cell and guide a direction for counterbalancing sustainability and photovoltaic performance of perovskite solar cells.