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

ABSTRACT

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] ₂ CdCl ₄ ( 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.