Yang Seok Jin, Kim Heesang, Kim Nammee
Department of Physics, Soongsil University, Seoul, 06978, Korea.
Integrative Institute of Basic Sciences, Soongsil University, Seoul, 06978, Korea.
Sci Rep. 2025 Aug 24;15(1):31134. doi: 10.1038/s41598-025-16548-7.
The structural asymmetry of Janus transition metal dichalcogenides gives rise to physical properties distinct from those of their symmetric counterparts. When Janus transition metal dichalcogenides are vertically stacked, their resulting heterostructure exhibits novel and enhanced electronic properties due to interactions between interfacial atoms, changes in electric dipole moments, and van der Waals interlayer interactions. In this study, we employ first-principles calculations based on density functional theory using the Vienna Ab initio Simulation Package to investigate the electronic properties of MoSSe-WSSe vertical Janus transition metal dichalcogenides heterostructures. By analyzing the density of states, charge density distribution, formation energy, bandgap, band alignment, and dipole moment, we identify key factors governing the electronic behavior of these heterostructures. Our calculation identifies the most favorable interfacial configuration and stacking type for synthesis. Furthermore, while the bandgap type is primarily dictated by the composition of interfacial atoms irrespective of the stacking type, its magnitude is influenced by both the interfacial atomic composition and stacking configuration. Notably, the total dipole moment is not merely the arithmetic sum of the dipole moments of the individual layers; rather, it is influenced by the interlayer coupling between the two layers. This trend can be explained by variations in the charge density distribution as a function of interlayer spacing. These findings suggest that the electronic properties of Janus heterostructures can be effectively tuned by modifying the interfacial atomic composition, stacking configuration, and interlayer distance, highlighting their potential for next-generation nanoelectronic applications.
Janus过渡金属二硫属化物的结构不对称性导致其物理性质与其对称对应物不同。当Janus过渡金属二硫属化物垂直堆叠时，由于界面原子之间的相互作用、电偶极矩的变化以及范德华层间相互作用，其形成的异质结构表现出新颖且增强的电子性质。在本研究中，我们使用基于密度泛函理论的第一性原理计算，借助维也纳从头算模拟包来研究MoSSe-WSSe垂直Janus过渡金属二硫属化物异质结构的电子性质。通过分析态密度、电荷密度分布、形成能、带隙、能带排列和偶极矩，我们确定了控制这些异质结构电子行为的关键因素。我们的计算确定了合成中最有利的界面构型和堆叠类型。此外，虽然带隙类型主要由界面原子的组成决定，与堆叠类型无关，但其大小受界面原子组成和堆叠构型两者的影响。值得注意的是，总偶极矩不仅仅是各层偶极矩的算术和；相反，它受两层之间的层间耦合影响。这种趋势可以通过电荷密度分布随层间距的变化来解释。这些发现表明，通过改变界面原子组成、堆叠构型和层间距离，可以有效地调节Janus异质结构的电子性质，突出了它们在下一代纳米电子应用中的潜力。
