Liu Bingmei, Xu Wangping, Long Xia, Cao Juexian
Department of Physics & Hunan Institute of Advanced Sensing and Information Technology, Xiangtan University, Xiangtan 411105, P. R. China.
Phys Chem Chem Phys. 2022 Aug 10;24(31):18777-18782. doi: 10.1039/d2cp02210a.
The phase transition in layered MoS has attracted wide attention but the detailed phase transition process is still unclear. Here, the H → T' phase transition mechanism of single- and bilayer MoS induced by lithium intercalation has been systematically studied using first principles. The results indicated that the lithium intercalation can effectively reduce the sliding barrier of the S atom layer. Moreover, we demonstrated that the phase transition process in bilayer MoS is induced by S atom transition one by one instead of the collective behavior of the S atoms. Importantly, we found that the phase transition process in bilayer MoS consists of the formation, diffusion and recombination of S vacancies, and the phase transition originates from interlayer lithium defects. In addition, the lithium defects cannot induce phase transition in monolayer MoS due to the larger sliding barrier of the S atom.
层状二硫化钼（MoS）中的相变引起了广泛关注，但详细的相变过程仍不清楚。在此，利用第一性原理系统地研究了锂嵌入诱导的单层和双层二硫化钼的H→T'相变机制。结果表明，锂嵌入可以有效降低硫原子层的滑动势垒。此外，我们证明了双层二硫化钼中的相变过程是由硫原子逐个跃迁引起的，而不是硫原子的集体行为。重要的是，我们发现双层二硫化钼中的相变过程包括硫空位的形成、扩散和复合，并且相变起源于层间锂缺陷。此外，由于硫原子的滑动势垒较大，锂缺陷不会在单层二硫化钼中诱导相变。
