把不同晶体结构和能带结构的二维纳米材料叠加并利用层间范德瓦耳斯力来构筑异质结，极有可能产生新的材料结构和物理性质及在未来信息器件方面的潜在应用价值。(Ge,Sn)Se与黑磷具有相似结构和外层价电子数并都是半导体且具有本征铁弹性。但(Ge,Sn)Se中载流子有效质量要小于黑磷并且分别在高温和室温表现出优异热电特性。(Ge,Sn)Se因不具有反演对称性表现出压电和铁电特性。GeSe/黑磷异质结中因存在自发电子-空穴分离是优异的光电材料，但是(Ge,Sn)Se/黑磷异质结方面的研究还较少。我们首先构筑(Ge,Sn)Se/黑磷异质结，研究自旋-轨道耦合效应、范德瓦耳斯力对不同层间叠加方式稳定性的影响及相应的能带结构特征，接着利用密度泛函理论结合非平衡格林函数的方法来研究异质结的量子输运特性及应力和电场的影响并设计一两种器件模型。最后，将研究内容扩展到(Ge,Sn)Se/过渡金属二硫化物异质结中去。

Two-dimensional (2D) nanomaterials have been extensively studied ever since a monolayer graphene was isolated from graphite by mechanical exfoliation in 2004. Thereafter, the interest is promptly extended to other nove 2D nanomaterials, such as hexagonal boron nitride, silicene, phosphorene, transition metal dichalcogenides, group-IV monochalcogenides, and so on. Furthermore, it is found that if one kind of 2D nanomaterials is placed upon other 2D nanomaterials to construct van der Waals (vdW) heterostructures, the systems will show some novel structures, physical properties and the pontential applies in the next-generation electronics. Recently, a new kind of novel 2D nanomaterials (group-IV monochalcogenides, (Ge,Sn)Se) has attracted great attentions. (Ge,Sn)Se monolayers are structurely similar and isoelectronic to monolayer phosphorene. In contrast with graphene, (Ge,Sn)Se and phosphorene are direct semiconductors and have the intrinsic ferroelasticity. However, the electron and hole effective mass in (Ge,Sn)Se monolayers are less than those in phosphorene. That is to say, (Ge,Sn)Se maybe have a higher mobility than phosphorene and are the promising candidates in electronic devices. Due to the lack of inversion symmetry in (Ge,Sn)Se monolayers, they show ferroelectricity and piezoelectricity, with piezoelectric constants higher than those in boronitrene and MoS2. Density functional theory predicts that the thermoelectric figure of merit reaches 3.27 or 2.76 along the armchair or zigzag directions with an optimal n-type carrier concentration in SnSe monolayer because of the exceptionally low lattice thermal conductivity. However, the thermoelectric figure of merits of SnSe would drastically reduce with the temperature decreasing. Moreover, density functional theory in combination with Boltzmann transport calculations show that the thermoelectric figure of merits of phosphorene reaches to 1 at room temperature. Thus, as expected, (Ge,Sn)Se/phosphorene vdW heterostructures will show better thermoelectric performance in a wider temperature region. Owing to the spontaneous electron-hole charge separation in GeSe/phosphorene vdW heterostructures, they are the promising candidates for high-performance optoelectronic devices. However, few papers on (Ge,Sn)Se/phosphorene vdW heterostructures have been reported. Therefore, we firstly construct (Ge,Sn)Se/phosphorene vdW heterostructures by taking into account the different stacking ways between (Ge,Sn)Se and phosphorene. Secondly, the formation energies are calculated to investigate the thermodynamic stability with density functional theory and the phonon spectra are caluclated to discuss the dynamical stability within density functional perturbation theory. Thirdly, the comparative calculations including van der Waals corrections and spin-orbital coupling interactions are carried out. Fourthly, the electric or thermoelectric transport properties are discussed within density functional theory in combination with non-equilibrium Green function. Furthermore, the effects of strains and vertical electric fields on electronic structures and transport properties are investigated. To understand the effect of electric fields, the redistribution of electron density as well as the transferred electrons between intra- and inter-layers are systemically calculated by the integration of electron density in real-space grids. At last, all the above-mentioned investigations will be expand to the studies on (Ge,Sn)Se/ transition metal dichalcogenides vdW heterostructures.