Oliva Nicoló, Casu Emanuele Andrea, Yan Chen, Krammer Anna, Rosca Teodor, Magrez Arnaud, Stolichnov Igor, Schueler Andreas, Martin Olivier J F, Ionescu Adrian Mihai
Nanoelectronic Devices Laboratory (NanoLab), École Polytechnique Fédérale de Lausanne (EPFL), 1015, Lausanne, Switzerland.
Nanophotonics and Metrology Laboratory (NAM), École Polytechnique Fédérale de Lausanne (EPFL), 1015, Lausanne, Switzerland.
Sci Rep. 2017 Oct 27;7(1):14250. doi: 10.1038/s41598-017-12950-y.
Junctions between n-type semiconductors of different electron affinity show rectification if the junction is abrupt enough. With the advent of 2D materials, we are able to realize thin van der Waals (vdW) heterostructures based on a large diversity of materials. In parallel, strongly correlated functional oxides have emerged, having the ability to show reversible insulator-to-metal (IMT) phase transition by collapsing their electronic bandgap under a certain external stimulus. Here, we report for the first time the electronic and optoelectronic characterization of ultra-thin n-n heterojunctions fabricated using deterministic assembly of multilayer molybdenum disulphide (MoS) on a phase transition material, vanadium dioxide (VO). The vdW MoS/VO heterojunction combines the excellent blocking capability of an n-n junction with a high conductivity in on-state, and it can be turned into a Schottky rectifier at high applied voltage or at temperatures higher than 68 °C, exploiting the metal state of VO. We report tunable diode-like current rectification with a good diode ideality factor of 1.75 and excellent conductance swing of 120 mV/dec. Finally, we demonstrate unique tunable photosensitivity and excellent junction photoresponse in the 500/650 nm wavelength range.
如果不同电子亲和力的n型半导体之间的结足够陡峭，就会表现出整流特性。随着二维材料的出现，我们能够基于多种材料实现薄的范德华（vdW）异质结构。与此同时，强关联功能氧化物也应运而生，它们能够在一定外部刺激下通过压缩其电子带隙表现出可逆的绝缘体-金属（IMT）相变。在此，我们首次报道了通过在相变材料二氧化钒（VO）上确定性组装多层二硫化钼（MoS）制备的超薄n-n异质结的电学和光电特性。vdW MoS/VO异质结将n-n结的优异阻挡能力与导通状态下的高电导率相结合，并且利用VO的金属态，在高施加电压或高于68°C的温度下可转变为肖特基整流器。我们报道了具有1.75的良好二极管理想因子和120 mV/dec的优异电导摆幅的可调谐二极管状电流整流。最后，我们展示了在500/650 nm波长范围内独特的可调谐光敏性和优异的结光响应。
