Boosting the light-driven pyroelectric response of poly(vinylidene difluoride) by constructing Mn-doped BZT-BCT/PVDF composites

Abstract

Poly(vinylidene difluoride) (PVDF) with lightweight and mechanically flexible features is prevalently used in designing pyroelectric photodetectors. However, the generated electrical signals are often limited by its low pyroelectric coefficient. In this work, Mn-doped BZT-BCT (BZTM_0.12-BCT) particles with a narrow bandgap and a high pyroelectric coefficient are introduced into a PVDF film to enhance its photo-pyroelectric response. The addition of BZTM_0.12-BCT positively impacts the content of the electroactive phase, crystallinity and photothermal conversion capability. These factors jointly enhance the photo-pyroelectric response. The PVDF composite film with a BZTM_0.12-BCT content of 10 wt% presents an optimal photo-pyroelectric current, about 30 times higher than that of the pure PVDF film. Besides, the composite film shows excellent visible response from 365 nm to 660 nm light zones and superior maintenance over 71% under great bending conditions and almost 100% under repeated periodic illuminations after 100 cycles. Furthermore, it is easy to control the amplitude and waveform of the output signals simply by regulating the frequency of the periodic illuminations, showing critical potential in the complex and changeable environments. This work provides a simple strategy to improve the photo-pyroelectric output of the PVDF film, making it a potential candidate for future self-powered applications.