Micropyramid silicon wafer with ZnO nanowires as high efficiency piezoelectric nanogenerator

The piezoelectric nanogenerator (PENG) is an important landmark in the development nanotechnology. The PENG, conventing mechanical energy to electrical energy in nanoscale, relies on the coupling of piezoelectric and semiconducting properties of nanomaterials. This approach offers a potential solution for harvesting energy from the environment for self-powered nanotechnology. How to improve the conversion efficiency is still one of the most factors for current PENG. Here, based on the fundamental research of piezoelectric nanogenerators, we propose a simple, robust, and scalable approach for fabricating a nanowire nanogenerator in which, ZnO nanowires is grown on the micro-pyramid textured surface of the silicon wafer and then a nanogenerator is fabricated by simply combine two substrates with ZnO nanowires face-to-face. The proposed geometry allows the nanogenerator to collect multi-faceted mechanical energy. This pyramid structure of the ZnONWs nanogenerators can generate piezoelectric current with an average signal about 3nA when the device was drove by ultrasonic waves at 40 kHz.