Electrostatic Force Mediated Work Function Modulation of Polyvinylidene crystalline Phases

We studied how the polarity of different phases of polyvinylidene fluoride (PVDF), a flexible and sensitive ferroelectric polymer, affects its work function. This is important for designing new flexible electronics and healthcare devices. We used Fourier transform infrared spectroscopy (FTIR) to identify the non-polar (α) and electroactive (γ and β) phases. We measured the water contact angle and surface potential to see how the phases changed the surface properties. We also used atomic and Kelvin probe microscopy (AFM and KPFM) to map the spherulite and surface potential variation of each phase. We used ultraviolet photoelectron spectroscopy (UPS) to measure the valence bands spectrum and work function of PVDF phases. We showed that the surface potential variation can enhance the charge generation by contact electrification in single material based multi-interfaces (αα < γγ < αγ).