Piezoelectricity in two dimensions: Graphene vs. molybdenum disulfide

作者：Xiaoxue Song, Fei Hui, Theresia Knobloch, Bingru Wang, Zhongchao Fan, Tibor Grasser, Xu Jing, Yuanyuan Shi, Mario Lanza · 发表于：Applied Physics Letters · 年份：2017 · DOI：10.1063/1.5000496 · 被引用次数：37 · 研究领域：Graphene research and applications、2D Materials and Applications、Advanced Sensor and Energy Harvesting Materials

The synthesis of piezoelectric two-dimensional (2D) materials is very attractive for implementing advanced energy harvesters and transducers, as these materials provide enormously large areas for the exploitation of the piezoelectric effect. Among all 2D materials, molybdenum disulfide (MoS2) has shown the largest piezoelectric activity. However, all research papers in this field studied just a single material, and this may raise concerns because different setups could provide different values depending on experimental parameters (e.g., probes used and areas analyzed). By using conductive atomic force microscopy, here we in situ demonstrate that the piezoelectric currents generated in MoS2 are gigantic (65 mA/cm2), while the same experiments in graphene just showed noise currents. These results provide the most reliable comparison yet reported on the piezoelectric effect in graphene and MoS2.