Enhanced interlayer interactions in Ni-doped <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:msub><mml:mi>MoS</mml:mi><mml:mn>2</mml:mn></mml:msub></mml:math> , and structural and electronic signatures of doping site

The crystal structure of MoS$_2$ with strong covalent bonds in plane and weak Van der Waals interactions out gives rise to interesting properties for applications such as solid lubrication, optoelectronics, catalysis, which can be enhanced by transition-metal doping. However, the mechanisms improvement even doped material unclear, we address theoretical calculations. Building on our previous work Ni-doping bulk 2H phase, now compare polytypes (1H monolayer 3R bulk), determine favorable sites Ni doping effect structure, electronic properties, layer dissociation energy. most intercalation/adatom are tetrahedral intercalation (like 2H) Mo-atop 1H. relative energies indicate a possibility phase change from substitution Mo or S. We find structural that used identify sites, including metallic behavior Mo-substituted 2H, in-gap states Mo- S-substituted 1H, could have optoelectronic applications. observe large enhancement interlayer Ni-doped MoS$_2$, opposite other transition metals. For lubrication applications, this increased energy mechanism low wear. Our systematic study shows concentration extrapolate low-doping limit. This insight into previously unclear how it detected experimentally, relation structures monolayers systems, under doping, interactions.