Femtosecond Laser Irradiation-Mediated MoS2-Metal Contact Engineering for High-Performance Field-Effect Transistors and Photodetectors
Femtosecond Laser Irradiation-Mediated MoS2-Metal Contact Engineering for High-Performance Field-Effect Transistors and Photodetectors
复制标题
用于高性能场效应晶体管和光电探测器的飞秒激光辐照介导的 MoS2 金属接触工程
DOI：
10.1021/acsami.1c12685
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发表时间：
2021-11-17
影响因子：
9.5
通讯作者：
Liu, Lei
中科院分区：
文献类型：
--
作者：
Huo, Jinpeng;Xiao, Yu;Liu, Lei
二维材料表现出有趣的电学和光学特性，使其成为下一代纳米电子器件的有希望的候选者。然而，二维材料对电极材料的高接触电阻往往限制了二维材料和器件的最终性能和潜力。在这项工作中，我们展示了一种局部飞秒（fs）激光照射工艺，以极大地减少mos2金属触点的电阻。对于机械剥离的MoS2，接触电阻降低超过三个数量级，显著提高了FET的整体性能。电阻降低的潜在机制是去除转移过程引起的有机污染，以及金扩散引起的界面费米能级钉钉（FLP）降低肖特基势垒电阻（R-SB），以及激光照射下金嵌入增强层间耦合导致层间电阻（R-int）降低。利用改进的MoS2-金属接触行为，开发了一种高性能的MoS2光电探测器，其光响应率为68.8 a W-1， V-ds很低，为0.5 V，比原始多层光电探测器高80倍。这种无污染、定点、通用的光子制造技术为复杂二维器件的集成提供了有效的工具，而mos2 -金属界面修饰的机制为设计二维材料-金属界面提供了新的途径。
2D materials exhibit intriguing electrical and optical properties, making them promising candidates for next-generation nanoelectronic devices. However, the high contact resistance of 2D materials to electrode material often limits the ultimate performance and potential of 2D materials and devices. In this work, we demonstrate a localized femtosecond (fs) laser irradiation process to substantially minimize the resistance of MoS2-metal contacts. A reduction of the contact resistance exceeding three orders of magnitude is achieved for mechanically exfoliated MoS2, which remarkably improves the overall FET performance. The underlying mechanisms of resistance reduction are the removal of organic contamination induced by the transfer process, as well as the lowering of Schottky barrier resistance (R-SB) attributed to interface Fermi level pinning (FLP) by Au diffusion, and the lowering of interlayer resistance (R-int) due to interlayer coupling enhancement by Au intercalation under fs laser irradiation. By taking advantage of the improved MoS2-metal contact behavior, a high-performance MoS2 photodetector was developed with a photoresponsivity of 68.8 A W-1 at quite a low V-ds of 0.5 V, which is similar to 80 times higher than the pristine multilayer photodetector. This contamination-free, site-specific, and universal photonic fabrication technique provides an effective tool for the integration of complex 2D devices, and the mechanism of MoS2-metal interface modification reveals a new pathway to engineer the 2D material-metal interface.