School of Materials Science and Engineering, Beihang University , Beijing 100191, P. R. China.
Department of Physics, South University of Science and Technology of China , Shenzhen 518005, P. R. China.
ACS Appl Mater Interfaces. 2017 Dec 6;9(48):42149-42155. doi: 10.1021/acsami.7b15288. Epub 2017 Nov 21.
van der Waals heterojunctions formed by stacking various two-dimensional (2D) materials have a series of attractive physical properties, thus offering an ideal platform for versatile electronic and optoelectronic applications. Here, we report few-layer SnSe/MoS van der Waals heterojunctions and study their electrical and optoelectronic characteristics. The new heterojunctions present excellent electrical transport characteristics with a distinct rectification effect and a high current on/off ratio (∼1 × 10). Such type-II heterostructures also generate a self-powered photocurrent with a fast response time (<10 ms) and exhibit high photoresponsivity of 100 A W, together with high external quantum efficiency of 23.3 × 10% under illumination by 532 nm light. Photoswitching characteristics of the heterojunctions can be modulated by bias voltage, light wavelength, and power density. The designed novel type-II van der Waals heterojunctions are formed from a combination of a transition-metal dichalcogenide and a group IV-VI layered 2D material, thereby expanding the library of ultrathin flexible 2D semiconducting devices.
由堆叠各种二维（2D）材料形成的范德华异质结具有一系列吸引人的物理性质，从而为多功能电子和光电子应用提供了理想的平台。在这里，我们报告了几层 SnSe/MoS 范德华异质结，并研究了它们的电学和光电特性。新的异质结具有出色的电输运特性，具有明显的整流效应和高电流开关比（约 1×10）。这种 II 型异质结构还产生了具有快速响应时间（<10 ms）的自供电光电流，并在 532nm 光照射下表现出 100 A W 的高光响应率，以及 23.3×10%的高光外量子效率。异质结的光电开关特性可以通过偏置电压、光波长和功率密度来调制。所设计的新型 II 型范德华异质结由过渡金属二卤化物和 IV-VI 族层状 2D 材料组合而成，从而扩展了超薄柔性 2D 半导体器件的库。
