Surface-Shielding Nanostructures Derived from Self-Assembled Block Copolymers Enable Reliable Plasma Doping for Few-Layer Transition Metal Dichalcogenides

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• 作者：Soonmin Yim ; Dong Min Sim ; Woon Ik Park ; Min-Jae Choi ; Jaesuk Choi ; Jaebeom Jeon ; Kwang Ho Kim and Yeon Sik Jung
• 刊名：Advanced Functional Materials
• 出版年：2016
• 出版时间：August 16, 2016
• 年：2016
• 卷：26
• 期：31
• 页码：5631-5640
• 全文大小：2398K
• ISSN：1616-3028

文摘

Precise modulation of electrical and optical properties of 2D transition metal dichalcogenides (TMDs) is required for their application to high-performance devices. Although conventional plasma-based doping methods have provided excellent controllability and reproducibility for bulk or relatively thick TMDs, the application of plasma doping for ultrathin few-layer TMDs has been hindered by serious degradation of their properties. Herein, a reliable and universal doping route is reported for few-layer TMDs by employing surface-shielding nanostructures during a plasma-doping process. It is shown that the surface-protection oxidized polydimethylsiloxane nanostructures obtained from the sub-20 nm self-assembly of Si-containing block copolymers can preserve the integrity of 2D TMDs and maintain high mobility while affording extensive control over the doping level. For example, the self-assembled nanostructures form periodically arranged plasma-blocking and plasma-accepting nanoscale regions for realizing modulated plasma doping on few-layer MoS₂, controlling the n-doping level of few-layer MoS₂ from 1.9 × 10¹¹ cm⁻² to 8.1 × 10¹¹ cm⁻² via the local generation of extra sulfur vacancies without compromising the carrier mobility.