Dual-Piezo-Charge Strategy in (1-0)-3 Single-Crystal Composite for Enhancing Underwater Acoustic Sensing

Piezoelectric ultrasonic transducers (PUTs) are extensively used in diverse technological fields, yet further enhancement in acoustic sensitivity and hydrostatic figure of merit d_hg_h have plateaued in conventional 1-3 piezocomposites, whose structures have remained largely unchanged for decades. Herein, we report a (1-0)-3 single-crystal piezocomposite (SCPC) based on the [011]-oriented Pb(In_1/2Nb_1/2)O₃-Pb(Mg_1/3Nb_2/3)O₃-PbTiO₃ (PIN-PMN-PT) single-crystal, featuring a dual-piezo-charge (DPC) mechanism arising from the piezoelectric and piezoelectret synergy effect. The ordered and polar 0-phase microholes with aligned dipoles are intentionally introduced in 1-phase piezo-pillars, yielding a uniquely low effective dielectric constant, reduced acoustic impedance, and DPC properties unattainable in conventional SCPCs. Both Simulations and experiments confirm that this DPC mechanism in (1-0)-3 SCPC enables an ultrahigh d_hg_h of ~ 8089 × 10^-15 m² N^-1, representing increases of 443.2% and 890.6% over commercial 1-3 SCPC and 1-3 piezoceramic composite, respectively. The engineered microhole structure and DPC strategy also significantly enhance underwater acoustic sensitivity while maintaining a broad - 3 dB bandwidth of 130 kHz, crucial for maritime safety and collision avoidance. Meanwhile, the long-term testing further verifies the PUT's operational stability. This design approach offers a promising pathway for next-generation piezocomposites and PUT technologies.