Mechanical-Chemical Coupled Synthesis for Long-Range Ordered Perovskites

Abstract Coupling mechanical and chemical effects during the crystal synthesis can lead to unexpected material attributes. The role of mechanical effects during the wet chemical synthesis of halide perovskite remains insufficiently explored, mainly due to its temporal asynchronization with the typical slower solvent evaporation-motivated chemical changes. In this study, we introduce mechanical shearing stress into a short temporal-window of crystal synthesis by using a fast-crystallization precursor system, which synergizes mechanical shearing effects with the atomic assembly thermodynamics of perovskite. This synthetic protocol facilitates cross-lengthscale influences, allowing macroscopic dynamic shearing to impact the atomic lattice rearrangement, growth, and facet orientation. Such an effect is consistently observed across atomic to inch-scale, culminating in films with long-range uniformity that are challenges via conventional methods. The as-synthesized perovskite films exhibit exceptional crystalline orientation and structural uniformity, demonstrating a significant Hermann’s orientation factor of -0.314 and leading to a remarkable power conversion efficiency of 25.90% on small area cell and exceeding 21% in a 70 cm2 solar module. This synthetic approach exemplifies the philosophy of utilizing mechanical shearing to foster the assembly of long-range ordered crystallographic lattice, thereby providing a new manufacturing route for synthesizing scalable high-quality perovskite films.