A Two-Dimensional Organic-Inorganic Hybrid Perovskite Ferroelectric for High-Performance Composite Magnetoelectric and Dual-Source Energy Harvesting.

Magneto-mechano-electric (MME) generators capable of simultaneously harvesting ubiquitous vibrational and magnetic-field energy are attractive candidates for self-powered systems. However, existing inorganic ceramic and polymeric materials are fundamentally constrained by a trade-off among transverse piezoelectric performance, manufacturability, and mechanical compliance, thereby limiting further advances in MME coupling. Here, we report a new Ruddlesden-Popper (RP)-type molecular ferroelectric, [DFCBA]2CdCl4 (1; DFCBA = 3,3-difluorocyclobutylammonium), which exhibits a large transverse piezoelectric response. Owing to the pronounced structural anisotropy of its layered framework, preferentially oriented 1@PVA composite films can be readily fabricated on Metglas substrates by simple spin coating. A cantilever-type MME generator based on this composite delivers a magnetoelectric (ME) voltage coefficient of 450 V cm-1 Oe-1 at approximately 50 Hz after geometric optimization, representing one of the highest ME voltage coefficients reported to date for molecule-based ME composites. The device also enables the simultaneous harvesting of magnetic-field and vibrational energy, exhibiting a pronounced energy-superposition effect under dual excitation and stable electrical output under practical operating conditions. These findings establish RP-type molecular ferroelectrics as a promising materials platform for high-performance MME generators and open new opportunities for multi-source energy harvesting and self-powered Internet of Things technologies.