Transformation of ZnS micropheres to non-centrosymmetric nanoplates for the fabrication of flexible piezoelectric nanogenerators: Electrode surface area modification for boosting the output performance

We report the transformation of ZnS particles from microsphere to 2D nanoplate having a non-centrosymmetric phase by optimizing growth parameters of hydrothermal method, and fabrication of flexible piezoelectric nanogenerators (PENGs). ZnS nanoplates-based PENG showed maximum open circuit voltage and short circuit current of ~ 3.8V and 1.8 μA, respectively. Thereafter, surface of aluminium (Al) electrode was modified by making parallel and cross-parallel lines using a cost-effective technique. Surface-modified Al-electrode-based PENG device generated ~ 6.6 and 2.5 times higher open circuit voltage and short circuit current, respectively, with a power density of ~ 41.5 μWcm-2. This device successfully used as portable electronics by flashing 15 red LEDs after charging a 1 μF capacitor up to 7.1V in 75s. Furthermore, the device exhibited noticeable electric output signals under various kinds of human body motions, which makes it a promising candidate for self-powered wearable sensor applications.