Molybdenum disulfide (MoS₂) exhibits exceptional mechanical and wear properties combined with thermal stability, which makes it an outstanding solid lubricant. While numerous studies have reported on the tribological behavior of few-layer pristine MoS₂, little attention has been given to the impact of defects, such as sulfur vacancies, which are inevitable during large-scale fabrications. Understanding the factors that affect friction at the atomic level is essential for the design and optimization of high-performance materials. Here, we present a systematic study of the tribology of one- and two-layer MoS₂ nanosheets, with controllably introduced atomic vacancies, performed by atomic force microscopy. We find that the friction coefficient of mono- and bilayer MoS₂ suffers more than a 3-fold increase from the as-prepared layer (with an initial defect density of 1 × 10¹² cm^–2) to those with an induced atomic defect density of 1.2 × 10¹³ cm^–2. Comparison of the results reported here with analogous results in graphene shows that MoS₂ presents an attractive high resilience of the friction coefficient to monatomic defect generation in the atomic defect density range typically obtained by scalable techniques.

中文翻译：

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MoS2 纳米片对诱导原子空位的高摩擦弹性：对纳米机电器件的影响

二硫化钼 (MoS ₂ ) 具有卓越的机械和磨损性能以及热稳定性，使其成为出色的固体润滑剂。虽然大量研究报告了几层原始MoS ₂的摩擦学行为，但很少关注缺陷的影响，例如硫空位，这在大规模制造过程中是不可避免的。了解原子水平上影响摩擦的因素对于高性能材料的设计和优化至关重要。在这里，我们通过原子力显微镜对一层和两层 MoS _{2纳米片的摩擦学进行了系统研究，其中可控地引入了原子空位。我们发现单层和双层MoS 2}的摩擦系数从所制备的层（初始缺陷密度为1 × 10 ¹² cm ^–2）到诱导原子缺陷密度的层增加了3倍以上1.2 × 10 ¹³ cm ^–2。本文报告的结果与石墨烯中的类似结果的比较表明，MoS ₂在通常通过可扩展技术获得的原子缺陷密度范围内对单原子缺陷产生具有有吸引力的高摩擦系数弹性。