Piezoelectricity Enhancement of Nanogenerators Based on PDMS and ZnSnO3 Nanowires through Micro-structuration.

The current trend for smart, self-sustainable and multifunctional technology demands for the development of energy harvesters based on widely available and environmentally friendly materials. In this context, ZnSnO3 nanostructures show a promising potential due to their high polarization, which can be explored in piezoelectric devices. Nevertheless, a pure phase of ZnSnO3 is hard to achieve due to its metastability and obtaining it in the form of nanowires is even more challenging. Although some groups have already reported the mixing of ZnSnO3 nanostructures with polydimethylsiloxane (PDMS) to produce a nanogenerator, the resultant polymeric film is usually flat and does not take advantage of an enhanced piezoelectric contribution achieved through its micro-structuration. Herein, a micro-structured composite of nanowires synthesized by a seed-layer free hydrothermal route mixed with PDMS (ZnSnO3@PDMS) is proposed to produce nanogenerators. A d33 value of 23 +/- 4 pm/V was obtained by PFM for a single ZnSnO3 nanowire. The performance of the nanogenerator with the optimized micro-structuration reaches an output voltage, current, and instantaneous power density of 120 V, 13 microA, and 230 microW.cm(-2), respectively. The micro-structuration introduced herein results in an enhancement of the piezoelectric effect of the ZnSnO3 nanowires. The performance of this nanogenerator enables lighting up multiple LEDs, thus proving great potential for wearables and portable electronics.