ENHANCED ENERGY HARVESTING PERFORMANCE OF FLEXIBLE PVDF PIEZOELECTRIC NANOGENERATORS USING SNS₂/SNSE₂ HETEROSTRUCTURE AS NANOFILLERS.

Abstract

In this study, we report the effect of 2D transition metal dichalcogenides (TMDCs) including SnS2, SnSe2, their heterostructure (SnS2/SnSe2), and Polyvinylidene fluoride (PVDF) based composite films for improved performance of piezoelectric nanogenerators (PENG). SnS2, SnSe2 and SnS2/SnSe2 heterostructure were synthesized using hydrothermal method. The TMDC materials were incorporated within a PVDF matrix to create flexible thin films using the solution-casting method to investigate the outcome of TMDCs as nanofillers within the PVDF polymer framework. XRD confirmed the phase purity of SnS2, SnSe2 and their heterostructure, while the Raman spectra verified vibrational modes indicating high crystallinity and interfacial coupling. The enhancement of piezoelectric behavior was revealed by FTIR spectroscopy which shows an increment in the crystallization of β-phase within PVDF, post adding TMDC nanofillers. PVDF/SnS2/SnSe2 heterostructure nanogenerator exhibited the highest value for peak-to peak open circuit voltage (Voc) of 13.20 V and short circuit current (Isc) of 0.87 µA. This increment is linked to the cumulative effect of the formation of a heterointerface, facilitating charge separation, enhanced stress transfer and polarization due to asymmetric charge distribution at the interface. The generated voltage from the PENG device was used to power an LED. This study, thereby gives novel insights into heterostructure engineering for energy harvesting applications.