Zhu Juntong, Xu Hao, Zou Guifu, Zhang Wan, Chai Ruiqing, Choi Jinho, Wu Jiang, Liu Huiyun, Shen Guozhen, Fan Hongyou
College of Energy , Soochow Institute for Energy and Materials Innovations, and Key Laboratory of Advanced Carbon Materials and Wearable Energy Technologies of Jiangsu Province , Soochow University , Suzhou 215006 , China.
Department of Electronic and Electrical Engineering , University College London , Torrington Place , London WC1E 7JE , U.K.
J Am Chem Soc. 2019 Apr 3;141(13):5392-5401. doi: 10.1021/jacs.9b00047. Epub 2019 Mar 20.
Due to remarkable electronic property, optical transparency, and mechanical flexibility, monolayer molybdenum disulfide (MoS) has been demonstrated to be promising for electronic and optoelectronic devices. To date, the growth of high-quality and large-scale monolayer MoS has been one of the main challenges for practical applications. Here we present a MoS-OH bilayer-mediated method that can fabricate inch-sized monolayer MoS on arbitrary substrates. This approach relies on a layer of hydroxide groups (-OH) that are preferentially attached to the (001) surface of MoS to form a MoS-OH bilayer structure for growth of large-area monolayer MoS during the growth process. Specifically, the hydroxide layer impedes vertical growth of MoS layers along the [001] zone axis, promoting the monolayer growth of MoS, constrains growth of the MoS monolayer only in the lateral direction into larger area, and effectively reduces sulfur vacancies and defects according to density functional theory calculations. Finally, the hydroxide groups advantageously prevent the MoS from interface oxidation in air, rendering high-quality MoS monolayers with carrier mobility up to ∼30 cm V s. Using this approach, inch-sized uniform monolayer MoS has been fabricated on the sapphire and mica and high-quality monolayer MoS of single-crystalline domains exceeding 200 μm has been grown on various substrates including amorphous SiO and quartz and crystalline Si, SiC, SiN, and graphene This method provides a new opportunity for the monolayer growth of other two-dimensional transition metal dichalcogenides such as WS and MoSe.
由于具有卓越的电子特性、光学透明度和机械柔韧性，单层二硫化钼（MoS）已被证明在电子和光电器件方面具有广阔前景。迄今为止，高质量、大规模单层MoS的生长一直是实际应用中的主要挑战之一。在此，我们提出一种MoS-OH双层介导的方法，该方法能够在任意衬底上制备英寸尺寸的单层MoS。这种方法依赖于一层优先附着在MoS的(001)表面上的羟基（-OH），以形成MoS-OH双层结构，从而在生长过程中实现大面积单层MoS的生长。具体而言，羟基层阻碍了MoS层沿[001]晶带轴的垂直生长，促进了MoS的单层生长，将MoS单层的生长仅限制在横向方向以形成更大的面积，并且根据密度泛函理论计算有效地减少了硫空位和缺陷。最后，羟基有利地防止了MoS在空气中发生界面氧化，从而得到载流子迁移率高达约30 cm² V⁻¹ s⁻¹的高质量MoS单层。利用这种方法，已在蓝宝石和云母上制备出英寸尺寸的均匀单层MoS，并在包括非晶SiO₂和石英以及晶体Si、SiC、SiN和石墨烯在内的各种衬底上生长出单晶域超过200 μm的高质量单层MoS。该方法为其他二维过渡金属二硫属化物（如WS₂和MoSe₂）的单层生长提供了新的机遇。
