Electrical Engineering Institute, École Polytechnique Fédérale de Lausanne (EPFL) , CH-1015 Lausanne, Switzerland.
Institute of Materials Science and Engineering, École Polytechnique Fédérale de Lausanne (EPFL) , CH-1015 Lausanne, Switzerland.
ACS Nano. 2017 Jun 27;11(6):6355-6361. doi: 10.1021/acsnano.7b02726. Epub 2017 May 26.
Transition metal dichalcogenides (TMDCs), together with other two-dimensional (2D) materials, have attracted great interest due to the unique optical and electrical properties of atomically thin layers. In order to fulfill their potential, developing large-area growth and understanding the properties of TMDCs have become crucial. Here, we have used molecular beam epitaxy (MBE) to grow atomically thin MoSe on GaAs(111)B. No intermediate compounds were detected at the interface of as-grown films. Careful optimization of the growth temperature can result in the growth of highly aligned films with only two possible crystalline orientations due to broken inversion symmetry. As-grown films can be transferred onto insulating substrates, allowing their optical and electrical properties to be probed. By using polymer electrolyte gating, we have achieved ambipolar transport in MBE-grown MoSe. The temperature-dependent transport characteristics can be explained by the 2D variable-range hopping (2D-VRH) model, indicating that the transport is strongly limited by the disorder in the film.
过渡金属二卤化物 (TMDCs) 与其他二维 (2D) 材料一起，由于原子层的独特光学和电学性质而引起了极大的兴趣。为了发挥它们的潜力，开发大面积生长和了解 TMDCs 的性质变得至关重要。在这里，我们使用分子束外延 (MBE) 在 GaAs(111)B 上生长原子薄的 MoSe。在生长的薄膜界面处没有检测到中间化合物。通过仔细优化生长温度，可以由于反转对称性的破坏，生长出具有仅两种可能晶体取向的高度对准的薄膜。生长的薄膜可以转移到绝缘衬底上，从而可以探测其光学和电学性质。通过使用聚合物电解质门控，我们已经在 MBE 生长的 MoSe 中实现了双极性输运。温度相关的输运特性可以用二维变程跳跃 (2D-VRH) 模型来解释，这表明输运受到薄膜中无序的强烈限制。
