School of Electrical and Computer Engineering and Birck Nanotechnology Center, Purdue University , West Lafayette, Indiana 47907, United States.
Globalfoundries Advanced Technology, Hopewell Junction, New York 12533, United States.
Nano Lett. 2015 Dec 9;15(12):8000-7. doi: 10.1021/acs.nanolett.5b03218. Epub 2015 Nov 13.
Artificial semiconductors with manufactured band structures have opened up many new applications in the field of optoelectronics. The emerging two-dimensional (2D) semiconductor materials, transition metal dichalcogenides (TMDs), cover a large range of bandgaps and have shown potential in high performance device applications. Interestingly, the ultrathin body and anisotropic material properties of the layered TMDs allow a wide range modification of their band structures by electric field, which is obviously desirable for many nanoelectronic and nanophotonic applications. Here, we demonstrate a continuous bandgap tuning in bilayer MoS2 using a dual-gated field-effect transistor (FET) and photoluminescence (PL) spectroscopy. Density functional theory (DFT) is employed to calculate the field dependent band structures, attributing the widely tunable bandgap to an interlayer direct bandgap transition. This unique electric field controlled spontaneous bandgap modulation approaching the limit of semiconductor-to-metal transition can open up a new field of not yet existing applications.
人工具有制造能带结构的半导体在光电领域开辟了许多新的应用。新兴的二维（2D）半导体材料过渡金属二卤族化合物（TMDs）具有较宽的能带隙范围，并在高性能器件应用中显示出潜力。有趣的是，层状 TMDs 的超薄体和各向异性材料性质允许通过电场对其能带结构进行广泛的修改，这对于许多纳米电子学和纳米光子学应用显然是理想的。在这里，我们使用双栅场效应晶体管（FET）和光致发光（PL）光谱法在双层 MoS2 中演示了连续的带隙调谐。密度泛函理论（DFT）用于计算依赖于电场的能带结构，将广泛可调的带隙归因于层间直接带隙跃迁。这种独特的电场控制的自发带隙调制接近半导体-金属转变的极限，可以开辟一个新的尚未存在应用的领域。
