Photochemically Induced Phase Change in Monolayer Molybdenum Disulfide
Photochemically Induced Phase Change in Monolayer Molybdenum Disulfide
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DOI：
10.3389/fchem.2019.00442
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发表时间：
2019-06-13
影响因子：
5.5
通讯作者：
Yan, Ruoxue
中科院分区：
文献类型：
--
作者：
Byrley, Peter;Liu, Ming;Yan, Ruoxue
单层过渡金属二硫属化物（TMD）是二维（2D）电子学、柔性、低功耗和透明电子学和光电子学的有希望的候选者。然而，基于TMD的器件的性能仍然受到相对低的载流子迁移率和半导体2D沟道材料与接触金属电极之间的大接触电阻的限制。相工程在单层TMD显示出巨大的希望，使制造高品质的异质相结构与控制的载流子迁移率和异质结材料，降低接触电阻。然而，迄今为止，在单层TMD中诱导相变的一般方法要么采用高度有害的有机金属化合物，要么与大规模、成本有效的器件制造具有有限的兼容性。在本文中，我们报告了一种新的光化学方法，诱导半导体金属相变单层二硫化钼在一个良性的化学环境中，通过一个台式的，具有成本效益的解决方案相过程，是兼容的大规模设备制造。结果表明，由单层二硫化钼的带隙吸收产生的光电子具有足够的化学势，以激活在给电子溶剂的存在下的相变。这种新颖的光化学相变机制推进了我们对2D过渡金属二硫属化物（TMD）相变的基本理解，并将在原子厚度的金属-半导体异质结构的制造中开辟新的收入，以提高载流子迁移率并降低基于TMD的电子和光电器件的接触电阻。
Monolayer transition metal dichalcogenide (TMDs) are promising candidates for two-dimensional (2D) ultrathin, flexible, low-power, and transparent electronics and optoelectronics. However, the performance of TMD-based devices is still limited by the relatively low carrier mobility and the large contact resistance between the semiconducting 2D channel material and the contact metal electrodes. Phase-engineering in monolayer TMDs showed great promise in enabling the fabrication of high-quality hetero-phase structures with controlled carrier mobilities and heterojunction materials with reduced contact resistance. However, to date, general methods to induce phase-change in monolayer TMDs either employ highly-hostile organometallic compounds, or have limited compatibility with large-scale, cost-effective device fabrication. In this paper, we report a new photochemical method to induce semiconductor to metallic phase transition in monolayer MoS2 in a benign chemical environment, through a bench-top, cost-effective solution phase process that is compatible with large-scale device fabrication. It was demonstrated that photoelectrons produced by the band-gap absorption of monolayer MoS2 have enough chemical potential to activate the phase transition in the presence of an electron-donating solvent. This novel photochemical phase-transition mechanism advances our fundamental understanding of the phase transformation in 2D transition metal dichalcogenides (TMDs), and will open new revenues in the fabrication of atomically-thick metal-semiconductor heterostructures for improved carrier mobility and reduced contact resistance in TMD-based electronic and optoelectronic devices.