Controlled synthesis of luminescent ZnS nanosheets with high piezoelectric performance for designing mechanical energy harvesting device

Abstract

For the first time, single-step fabrication of two-dimensional nanosheets of zinc sulfide (ZnS) was achieved employing flexible aluminum (Al) foil substrate using hydrothermal technique at 140 °C for ∼4 h. Indium doped Tin Oxide (ITO) coated on PET (Polyethylene Terephthalate) substrate and ZnS deposited Al foil as a top and bottom electrodes were used to fabricate a piezoelectric device. To generate an electric potential, the top ITO electrode was tapped on the ZnS nanosheets. The open-circuit voltage, VOC of ∼400 mV was obtained and analyzed for ZnS nanosheets based nanogenerator with gentle finger taping. However, the highest output for the single nanogenerator was found to be ∼600 mV by applying toe pressure. Additionally, switching polarity and superposition experiments were utilized to confirm the nanogenerator's performance, with the findings confirming piezo-electric voltage output. This study investigates the new potential for a ZnS-based high-efficient energy harvester that can scavenge biomechanical energy for next-generation flexible self-powered electronics devices as well as a good replacement for ZnO nanosheets in 2D nanostructured based nanogenerator devices due to its simple single-step production process, low cost, and high output gain.