Enantiomeric Fe(II)-incorporated organic-inorganic hybrid crystals for energy harvesting

Hybrid organic-inorganic piezoelectric materials, characterized by their tunable structure and inherent mechanical flexibility, are garnering significant attention for their potential applications in energy harvesting devices. Herein, we introduce a pair of Fe(II)-incorporated hybrid enantiomeric piezoelectric materials, designed as (R/S-3-hydroxyquinuclidium)₂FeCl₄ [(R/S-HQ)₂FeCl₄]. The enantiomers show a piezoelectric coefficient (d₃₃) of 21 pC/N and a high piezoelectric voltage coefficient (g₃₃) of 408 × 10^-3 V m N^-1, surpassing that of conventional piezoelectric polymer PVDF. Additionally, (R/S-HQ)₂FeCl₄ demonstrates significant dielectric permittivity switching and excellent cyclic stability. Moreover, in a piezoelectric generation device, this device produces a peak-to-peak output voltage of approximately 2.0 V, and displays a small deviation of only ±0.1 V after 60 days, confirming the long-term excellent output stability. This work highlights their considerable potential for integration into self-powered low-voltage electronic devices and energy harvesting systems.