Enantiomeric Fe(ii)-incorporated organic–inorganic hybrid crystals for energy harvesting†

Abstract

Hybrid organic–inorganic piezoelectric materials, characterized by their tunable structure and inherent mechanical flexibility, are garnering significant attention for their potential applications in electronic sensors and 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⁻¹ and a high piezoelectric voltage coefficient (g₃₃) of 408 × 10⁻³ V m N⁻¹, surpassing that of the conventional piezoelectric polymer PVDF. Additionally, (R/S-HQ)₂FeCl₄ demonstrates significant dielectric permittivity switching and excellent cycling stability. Moreover, in a piezoelectric generation device, this material produces a peak-to-peak output voltage of approximately 2.0 V and shows a small deviation of only ±0.1 V after 60 days, confirming its long-term excellent output stability. This work highlights its considerable potential for integration into self-powered low-voltage electronic devices and energy harvesting systems.