Controlled Doping of Vacancy-Containing Few-Layer MoS2 via Highly Stable Thiol-Based Molecular Chemisorption

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• 作者：Dong Min Sim ; Mincheol Kim ; Soonmin Yim ; Min-Jae Choi ; Jaesuk Choi ; Seunghyup Yoo ; Yeon Sik Jung
• 刊名：ACS Nano
• 出版年：2015
• 出版时间：December 22, 2015
• 年：2015
• 卷：9
• 期：12
• 页码：12115-12123
• 全文大小：672K
• ISSN：1936-086X

文摘

MoS₂ is considered a promising two-dimensional active channel material for future nanoelectronics. However, the development of a facile, reliable, and controllable doping methodology is still critical for extending the applicability of MoS₂. Here, we report surface charge transfer doping via thiol-based binding chemistry for modulating the electrical properties of vacancy-containing MoS₂ (v-MoS₂). Although vacancies present in 2D materials are generally regarded as undesirable components, we show that the electrical properties of MoS₂ can be systematically engineered by exploiting the tight binding between the thiol group and sulfur vacancies and by choosing different functional groups. For example, we demonstrate that NH₂-containing thiol molecules with lone electron pairs can serve as an n-dopant and achieve a substantial increase of electron density (螖n = 3.7 脳 10¹² cm^鈥?). On the other hand, fluorine-rich molecules can provide a p-doping effect (螖n = 鈭?.0 脳 10¹¹ cm^鈥?) due to its high electronegativity. Moreover, the n- and p-doping effects were systematically evaluated by photoluminescence (PL), X-ray photoelectron spectroscopy (XPS), and electrical measurement results. The excellent binding stability of thiol molecules and recovery properties by thermal annealing will enable broader applicability of ultrathin MoS₂ to various devices.