二维半导体异质结MoS2/MoSe2中一维量子阱形成机制的电子显微学研

二维半导体异质结MoS₂/MoSe₂中一维量子阱形成机制的电子显微学研

庞靖博，时金安，李  昂，李林璇，朱俊桐^*，周  武

（中国科学院大学，物理科学学院，北京100049）

摘  要  本文使用两步化学气相沉积法（CVD）成功合成了单层二维半导体MoS₂/MoSe₂面内异质结，通过扫描透射电子显微学（STEM）对异质结中不同类型的量子阱进行了原子尺度结构和局域应力分析，探索了二维半导体材料中，不同结构特征处诱导形成一维量子阱结构的机理。主要包括：1）晶格失配的二维半导体异质结界面处周期性位错阵列诱导形成的量子阱超晶格；2）二维半导体晶格内非60°晶界所包含的周期性位错诱导形成周期可控的量子阱超晶格；3）由连续4|8元环结构组成的60°晶界诱导形成的超长单一量子阱结构。

关键词  MoS₂/MoSe₂异质结；位错；应力；量子阱；低电压STEM

中图分类号：O76；TG115.21⁺5.3  文献标识码：A   doi:10.3969/j.issn.1000-6281.2024.01.004

Electron microscopy study of the formation mechanism of one-dimensional quantum well in two-dimensional semiconductor MoS₂/MoSe₂ heterostructures

PANG Jing-bo，SHI Jin-an，LI Ang, LI Lin-xuan，ZHU Jun-tong*，ZHOU Wu

(School of Physical Sciences, University of Chinese Academy of Sciences, Beijing 100049, China)

Abstract  In this paper, we reported the successful synthesis of a monolayer two-dimensional (2D) semiconductor MoS₂/MoSe₂ lateral heterostructure by a two-step chemical vapor deposition (CVD) method. The atomic-scale structure and local strain distribution of various types of quantum wells obtained in this lateral MoS₂/MoSe₂ heterostructure were systematically analyzed by aberration-corrected low-voltage scanning transmission electron microscopy (STEM) to explore the formation mechanism of 1D quantum well structures at different structural features in the 2D semiconductor lattice. The exploration mainly included: 1) MoS₂ quantum well superlattices induced by the periodic mis-fit dislocation arrays at the lateral hetero-interface with mismatched lattices; 2) MoS₂ quantum well superlattices with controlled period induced by the periodic dislocation arrays at non-60° grain boundaries in the MoSe₂ lattice; and 3) ultra-long isolated quantum wells induced by 60° grain boundaries consisting of continuous 4|8 membered ring structures.

Keywords   MoS₂/MoSe₂ heterostructure; dislocation; strain; quantum well; low-voltage STEM

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