Pyroelectricity in low electric field induced δ-PVDF nanostructures for self-powered applications

In ferroelectric polymers, Polyvinylidene fluoride (PVDF) is an excellent semi-crystalline polymer candidate having non-linear and electroactive properties. These properties govern the piezo-, pyro- and ferro-electric behavior of this material. [1, 2] In all the polymorphs of PVDF, δ-phase PVDF has been least explored phase due to its processing limitation, as it requires higher strength of electric field to achieve this particular phase. [2, 3] Recently, we have demonstrated a new approach to induce the δ-phase in PVDF at the lowest possible electric field till date. [4] The nanoscale ferroelectricity and converse piezoelectric properties of these nanoparticles have explored extensively in this work through piezo response force microscopy (PFM). Further to explore the pyroelectric behavior of the fabricated δ-phase PVDF nanostructures, we have extended the study with the different thermal stimuli. The temperature dependent stimuli response in terms of ferroelectric, dielectric and pyroelectric properties of δ-PVDF nanostructures, are the focus of this study, with the promising results, as of the β-phase polymorph of PVDF. Simultaneously, we have also tried to study the 2D correlation spectroscopy behavior, under the influence of the temperature in these nanostructures . Further, we have demonstrated the application of the δ-PVDF nanostructures as a self-powered pyroelectric energy harvester device and sensor purposes.

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4. V. Gupta, A. Babu, S.K. Ghosh, Z. Mallick, H.K. Mishra, D. Saini, D. Mandal, Appl. Phys. Lett. 119, 252902, (2021).