Atomic-thick 2D MoS2/insulator interjection structures for enhancing nanogenerator output

Ultra-small size and large electric output are highly desirable for piezoelectric nanogenerators for powering nanodevices. However, ultra-small size usually leads to low output. Here, we simulated the output performance of MoS2 nanogenerators based on atomic-thick 2D MoS2/insulator interjection structures and their rational integration. We showed that the output performance is greatly increased by selecting SiO2 as the insulator material, decreasing the thickness of insulator layers and increasing the side length of MoS2 unit layers. When mechanically resonant with external pressure at a frequency of 215 MHz, the output generated from our rationally designed nanogenerator (70 mu m x 70 mu m x 5.2 mu m) reaches 36 mW (corresponding to an average power density of 735 W cm(-2)) and this output was able to directly power some nanodevices that usually need several milliwatts. Such a high power-density positions our rationally designed nanogenerator as a first-class high-efficiency nanogenerator. In addition, a significantly high instantaneous conversion efficiency of 71% from mechanical energy to electrical energy can be achieved. Our work may give some suggestions for the rational design and experimental realization of ultra-small and high-output nanogenerators.