Enhancing the Output Charge Density of TENG via Building Longitudinal Paths of Electrostatic Charges in the Contacting Layers.

The surface charge density of the tribolayer is the most parameter for developing a high performance triboelectric nanogenerator (TENG). Most previous works focused on the surface structural/chemical modification. Nevertheless, the internal space of the tribolayer and its mechanism exploration were less investigated. Herein, in this work, internal-space-charge zones are built through imbedding ravines and gullies in criss-crossed gold layers in the near-surface of the tribolayer, which leads to the high output performance of TENG. As experimental results manifest, the transfer charge density of gold-PDMS TENG (G-TENG) reaches 168 μC m-2. Through theoretical analyses, it is determined that gold layers act as the passageways and traps of the triboelectric charges when the charges drift to the internal space of the tribomaterial. Moreover, the transport and storage process of triboelectric charges in the frictional layer are investigated comprehensively by quantum mechanics for the first time. The calculation method of the output current of TENG is proposed, and the theoretical calculation results coincide with the test results well. The results verify the application of the theoretical model and help with the construction and development of the theoretical system of TENG. Meanwhile, the relative results can be directly attained by this new theoretical model, and it is possible to make full use of the theoretical analysis to achieve a better performance for TENG. This study paves an easy and novel way for enhancing the charge density of the tribolayer by internal space construction and a new underlying theoretical model.