Vertical contact-separation mode triboelectric generator (TEG) based on lead-free perovskite, zinc stannate (ZnSnO 3 )-polyvinylidene fluoride (PVDF) composite and polyamide-6 (PA6) membrane is demonstrated. For the 5wt% PVDF-ZnSnO 3 nanocomposites, the facile phaseinversion method provides a simple route to achieve high crystallinity and β-phase with a piezoelectric coefficient d 33 of -65 pmV -1 , as compared to -44 pmV -1 for pristine PVDF membranes. Consequently, at a cyclic excitation impact of 490 N/3 Hz, the PVDF-ZnSnO 3 /PA6 based TEGs provide a significantly higher voltage of 520 V and a current © 2016. This manuscript version is made available under the Elsevier user license http://www.elsevier.com/open-access/userlicense/1.0/ 2 density of 2.7 mAm -2 (corresponding charge density of 62.0 µCm -2 ), as compared to the pristine PVDF-PA6 TEG which provides up to 300 V with a current density of 0.91 mAm -2(corresponding to a charge density of 55.0 µCm -2 ). This increase in the electrical output can be attributed to not only the enhanced polarisation of PVDF by ZnSnO 3 leading to an increase in the β-phase content, but also to the surface charge density increase by stress induced polarisation of ZnSnO 3 , leading to the generation of stronger piezoelectric potential.The work thus introduces a novel method of enhancing the surface charge density via the addition of suitable high polarization piezoelectric materials thus eliminating the need for prior charge injection for fluoropolymer membranes.

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The AC conductivity response in a broad frequency range of disordered materials is of great interest not only for technological applications, but also from a theoretical point of view. The Jonscher's power exponent value, and its temperature dependence, is a very important parameter in dielectric data analysis as well as the physical interpretation of conduction mechanisms in disordered materials. In some cases the power exponent of AC conductivity has been reported to be greater than 1 at the low frequency regime. This fact seems to contradict the universal dynamic response. The present work focuses on the analysis of dielectric spectroscopy measurements in polymeric materials, below ~100 MHz. The apparent power exponent n gets values in the range 0

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