Tunable Band Gap Photoluminescence from Atomically Thin Transition-Metal Dichalcogenide Alloys

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• 作者：Yanfeng Chen ; Jinyang Xi ; Dumitru O. Dumcenco ; Zheng Liu ; Kazu Suenaga ; Dong Wang ; Zhigang Shuai ; Ying-Sheng Huang ; Liming Xie
• 刊名：ACS Nano
• 出版年：2013
• 出版时间：May 28, 2013
• 年：2013
• 卷：7
• 期：5
• 页码：4610-4616
• 全文大小：543K
• 年卷期：v.7,no.5(May 28, 2013)
• ISSN：1936-086X

文摘

Band gap engineering of atomically thin two-dimensional (2D) materials is the key to their applications in nanoelectronics, optoelectronics, and photonics. Here, for the first time, we demonstrate that in the 2D system, by alloying two materials with different band gaps (MoS₂ and WS₂), tunable band gap can be obtained in the 2D alloys (Mo_1鈥?i>xW_xS₂ monolayers, x = 0鈥?). Atomic-resolution scanning transmission electron microscopy has revealed random arrangement of Mo and W atoms in the Mo_1鈥?i>xW_xS₂ monolayer alloys. Photoluminescence characterization has shown tunable band gap emission continuously tuned from 1.82 eV (reached at x = 0.20) to 1.99 eV (reached at x = 1). Further, density functional theory calculations have been carried out to understand the composition-dependent electronic structures of Mo_1鈥?i>xW_xS₂ monolayer alloys.

Keywords:

two-dimensional material; alloy; transition-metal dichalcogenide; band gap; photoluminescence; density functional theory calculation