Semiconductor-metal transition in semiconducting bilayer sheets of transition-metal dichalcogenides
Semiconductor-metal transition in semiconducting bilayer sheets of transition-metal dichalcogenides
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DOI：
10.1103/physrevb.86.075454
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发表时间：
2012-08-24
影响因子：
3.7
通讯作者：
Singh, Abhishek K.
中科院分区：
文献类型：
--
作者：
Bhattacharyya, Swastibrata;Singh, Abhishek K.
使用第一性原理计算，我们表明，通过施加垂直压缩压力，可以平滑地减小半导体过渡金属二硫属化物（TMD）双层片的带隙。这些材料在临界压力下经历普遍可逆的半导体到金属（S-M）转变。 S-M转变归因于费米能级能带简并性的提升，这是由于电荷从金属转移到硫族元素的层间相互作用引起的。即使在使用混合泛函和 GW 方法合并带隙校正后，也可以重现 S-M 跃迁。在较宽的能量范围内以受控方式调节 TMD 的带隙的能力为其在各种应用中的使用提供了可能性。
Using first-principles calculations we show that the band gap of bilayer sheets of semiconducting transition-metal dichalcogenides (TMDs) can be reduced smoothly by applying vertical compressive pressure. These materials undergo a universal reversible semiconductor-to-metal (S-M) transition at a critical pressure. The S-M transition is attributed to lifting of the degeneracy of the bands at the Fermi level caused by interlayer interactions via charge transfer from the metal to the chalcogen. The S-M transition can be reproduced even after incorporating the band gap corrections using hybrid functionals and the GW method. The ability to tune the band gap of TMDs in a controlled fashion over a wide range of energy opens up the possibility for its usage in a range of applications.