Kim Tae In, Park Ick-Joon, Kang Sumin, Kim Taek-Soo, Choi Sung-Yool
School of Electrical Engineering, Graphene/2D Materials Research Center, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 34141, Korea.
Department of Electrical and Electronic Engineering, Joongbu University, Goyang 10279, Korea.
ACS Appl Mater Interfaces. 2021 May 12;13(18):21299-21309. doi: 10.1021/acsami.1c02562. Epub 2021 Apr 28.
Two-dimensional transition-metal dichalcogenides (TMDs) are of particular interest as a new active material for future triboelectric nanogenerators (TENGs) owing to their excellent electrical properties, optical transparency, flexibility, ultrathin thickness, and biocompatibility. Here, we propose a new approach to engineer the surface of TMDs via conjugation with thiolated ligands having different alkane chain lengths and to develop TMD-based TENG devices that exhibit enhanced output performance for the first time. The triboelectric charging behaviors of ligand-conjugated TMDs are successfully investigated, and the electrical output performance of TMD TENGs based on TMD-to-polymer device geometries with a vertical contact-separation mode is dramatically improved, exhibiting an output voltage of 12.2 V and a power density of 138 mW/m. Furthermore, the ligand-conjugated TMD TENG device exhibits a highly stable operation under repeated contact and separation over 10 000 cycles, as well as high chemical stability, as a result of novel defect engineering via thiolated ligand conjugation. Detailed investigation reveals that the improved performance of the ligand-conjugated TMD TENG device originates from the synergistic effect of defect engineering and the p-type doping effect of TMDs, correlated with the increased electric potential difference between triboelectric layers. These findings provide a new potential of TMDs as a promising building block for the next-generation energy harvesting system.
二维过渡金属二硫属化物（TMDs）因其优异的电学性能、光学透明度、柔韧性、超薄厚度和生物相容性，作为未来摩擦电纳米发电机（TENGs）的新型活性材料而备受关注。在此，我们提出一种新方法，通过与具有不同烷烃链长度的硫醇化配体共轭来设计TMDs的表面，并首次开发出具有增强输出性能的基于TMDs的TENG器件。成功研究了配体共轭TMDs的摩擦起电行为，基于具有垂直接触-分离模式的TMD-聚合物器件几何结构的TMD TENGs的电输出性能得到显著改善，输出电压为12.2 V，功率密度为138 mW/m。此外，由于通过硫醇化配体共轭进行的新型缺陷工程，配体共轭TMD TENG器件在超过10000次循环的重复接触和分离下表现出高度稳定的运行，以及高化学稳定性。详细研究表明，配体共轭TMD TENG器件性能的提高源于缺陷工程的协同效应和TMDs的p型掺杂效应，这与摩擦电层之间增加的电势差相关。这些发现为TMDs作为下一代能量收集系统的有前途的构建块提供了新的潜力。
