Wuxi Branch of Jiangsu Province Special Equipment Safety Supervision and Inspection Institute , Wuxi 214174 , China.
School of Chemistry, Physics and Mechanical Engineering and Institute for Future Environments , Queensland University of Technology , Brisbane , QLD 4000 , Australia.
ACS Appl Mater Interfaces. 2019 Oct 23;11(42):39077-39087. doi: 10.1021/acsami.9b13645. Epub 2019 Oct 9.
Elemental alloying in monolayer, two-dimensional (2D) transition metal dichalcogenides (TMDs) promises unprecedented ability to modulate their electronic structure leading to unique optoelectronic properties. MoS monolayer based photodetectors typically exhibit a high photoresponsivity but suffer from a low response time. Here we develop a new approach for Sn alloying in MoS monolayers based on the synergy of the customized chemical vapor deposition (CVD) and the effects of common salt (NaCl) to produce high-quality and large-size MoSnS ( < 0.5) alloy monolayers. The composition difference results in different growth behaviors; Mo dominated alloys ( < 0.5) exhibit uniform and large size (up to 100 μm) triangular monolayers, while Sn-dominated alloys ( > 0.5) present multilayer grains. The MoSnS ( < 0.5) based photodetectors and phototransistors exhibit a maximum responsitivity of 12 mA/W and a minimum response time of 20 ms, which is faster than most reported MoS-based photodetectors. This work offers new perspectives for precision 2D alloy engineering to improve the optoelectronic performance of TMD-based photodetectors.
单层、二维（2D）过渡金属二卤化物（TMD）中的元素合金化有望前所未有地调节其电子结构，从而产生独特的光电性能。基于 MoS 单层的光电探测器通常表现出高光电响应率，但响应时间却很短。在这里，我们开发了一种新的方法，通过定制化学气相沉积（CVD）和常见盐（NaCl）的协同作用，在 MoS 单层中进行 Sn 合金化，从而产生高质量和大尺寸的 MoSnS（<0.5）合金单层。组成差异导致不同的生长行为；Mo 占主导的合金（<0.5）表现出均匀且大尺寸（高达 100 μm）的三角形单层，而 Sn 占主导的合金（>0.5）则呈现多层晶粒。基于 MoSnS（<0.5）的光电探测器和光电晶体管表现出 12 mA/W 的最大响应度和 20 ms 的最小响应时间，这比大多数报道的基于 MoS 的光电探测器都要快。这项工作为精确的 2D 合金工程提供了新的视角，以改善基于 TMD 的光电探测器的光电性能。
