Outside front cover image: The control of interlayer stacking constitutes a key degree of freedom that offers substantial potential for nextgeneration electronic and optoelectronic applications. For materials such as NbSe2, achieving precise control over both lattice alignment and stacking polytype remains a great challenge. The methods grew mono-oriented rhombohedral-stacked (R-stacked) NbSe2 ribbons on c-plane sapphire substrates by step-guided epitaxy. Symmetry breaking in c-plane sapphire enables R-stacking, as atomic steps in the substrate influence the NbSe2 layers. Experiments and theoretical calculations reveal that the atomic steps are closely linked with the oriented aligned R-stacked NbSe2 ribbons, which simultaneously guide the orientation and the R-stacking of NbSe2 layers. (https://onlinelibrary.wiley.com/doi/full/10.1002/smm2.70066)
Li et al. (2026) studied this question.