A novel BAs/CrS van der Waals heterostructure is manufactured and the stability, electronic and optical properties of the heterostructure under biaxial strain are researched. The formation of the heterostructure makes CrS, which is originally a conductor, shows the properties of semiconductor. The BAs/CrS heterostructure with a small band gap of 0.24 eV has typical type-II heterostructure characteristics. Under the action of the built-in election field (), the heterostructure manifests a Z-scheme peculiarity which can help it participate into water splitting reaction. Under biaxial strains, the binding energy of the heterostructure shows an increasing trend with the increase of strain, and the band structure changes obviously with biaxial strain especially around Fermi level. The heterostructure will transform from type-II to type-I and even transform to metal under biaxial strain regulation. The absorption peak of the heterostructure moves in succession to the short wave region as the magnitude of the compressive strain increases, while under tensile strain, the absorption peak of the heterostructure moves to the long wave region in succession as the magnitude of the tensile strain increases. Our results provide an essential guidance for tuning the electronic properties of the heterostructure through the powerful means of the strain engineering, which has great significance for practical optoelectronic device applications.

中文翻译：

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BAs/CrS2 范德华异质结中电子结构的转变


制备了一种新型BAs/CrS范德华异质结构，并研究了该异质结构在双轴应变下的稳定性、电子和光学性能。异质结构的形成使得原本是导体的CrS呈现出半导体的特性。带隙小至0.24 eV的BAs/CrS异质结构具有典型的II型异质结构特征。在内置选举场（）的作用下，异质结构表现出Z型特性，有助于其参与水分解反应。在双轴应变下，异质结构的结合能随着应变的增加呈现增加的趋势，能带结构随双轴应变变化明显，特别是在费米能级附近。在双轴应变调节下，异质结构会从II型转变为I型，甚至转变为金属。随着压应变大小的增大，异质结构的吸收峰依次向短波区移动，而在拉应变下，随着拉应变大小的增大，异质结构的吸收峰依次向长波区移动。我们的研究结果为通过应变工程的强大手段调节异质结构的电子特性提供了重要的指导，这对于实际的光电器件应用具有重要意义。