A Flexible Composite Mechanical Energy Harvester from a Ferroelectric Organoamino Phosphonium Salt

A new binary organic salt diphenyl diisopropylamino phosphonium hexaflurophosphate (DPDP⋅PF 6 ) was shown to exhibit a good ferroelectric response and employed for mechanical energy harvesting application. The phosphonium salt crystallizes in the monoclinic noncentrosymmetric space group Cc and exhibits an H‐bonded 1D chain structure due to N−H⋅⋅⋅F interactions. Ferroelectric measurements on the single crystals of DPDP⋅PF 6 gave a well‐saturated rectangular hysteresis loop with a remnant ( P r ) polarization value of 6 μC cm −2 . Further, composite devices based on polydimethylsiloxane (PDMS) films for various weight percentages (3, 5, 7, 10 and 20 wt %) of DPDP⋅PF 6 were prepared and examined for power generation by using an impact test setup. A maximum output peak‐to‐peak voltage ( V PP ) of 8.5 V and an output peak‐to‐peak current ( I PP ) of 0.5 μA was obtained for the non‐poled composite film with 10 wt % of DPDP⋅PF 6 . These results show the efficacy of organic ferroelectric substances as potential micropower generators.