Facile Fabrication of Large‐Area and High‐Quality Organic–Inorganic Hybrid Perovskite Ferroelectric Films Through Electrohydrodynamic Printing

Traditional oxide ferroelectrics have long struggled to produce flexible, large-area, and high-quality thin films at low temperatures, despite their good piezoelectric activity. Organic-inorganic hybrid perovskite ferroelectrics (OIHPFs), by contrast, are gaining popularity as promising candidates for next-generation flexible self-powered electric devices due to their easy solution-processability, structural adjustability, mechanical flexibility, and superior piezoelectric performance. However, their practical use is hindered by a lengthy single-crystal growing period and the absence of a truly effective large-area film manufacturing technique. To address these challenges, a simple electrohydrodynamic (EHD) printing technology is first proposed to in situ manufacture large-area, high-quality OIHPF crystals or flexible films at low temperatures, without substrate or size limitations. The obtained TMCM-CdBrCl₂ film has a high coverage of 99.83%. Notably, it has a crystallinity of 80.35% and a superior piezoelectric coefficient that is 72% and 5.8 times higher than that of the non-EHD-printed sample, respectively. The flexible piezoelectric nanogenerator (PENG) based on this film can endure over 200 000 bending cycles-the highest value recorded to date. This approach also shows strong feasibility and broad applicability in creating different OIHPF films or crystals, providing valuable scientific insight for the large-scale and integrated development of flexible OIHPF-based electronics.