Extraordinarily Bound Quasi-One-Dimensional Trions in Two-Dimensional Phosphorene Atomic Semiconductors

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• 作者：Renjing Xu ; Shuang Zhang ; Fan Wang ; Jiong Yang ; Zhu Wang ; Jiajie Pei ; Ye Win Myint ; Bobin Xing ; Zongfu Yu ; Lan Fu ; Qinghua Qin ; Yuerui Lu
• 刊名：ACS Nano
• 出版年：2016
• 出版时间：February 23, 2016
• 年：2016
• 卷：10
• 期：2
• 页码：2046-2053
• 全文大小：434K
• ISSN：1936-086X

文摘

We report a trion (charged exciton) binding energy of ∼162 meV in few-layer phosphorene at room temperature, which is nearly 1–2 orders of magnitude larger than those in two-dimensional (2D) transition metal dichalcogenide semiconductors (20–30 meV) and quasi-2D quantum wells (∼1–5 meV). Such a large binding energy has only been observed in truly one-dimensional (1D) materials such as carbon nanotubes, whose optoelectronic applications have been severely hindered by their intrinsically small optical cross sections. Phosphorene offers an elegant way to overcome this hurdle by enabling quasi-1D excitonic and trionic behaviors in a large 2D area, allowing optoelectronic integration. We experimentally validated the quasi-1D nature of excitonic and trionic dynamics in phospherene by demonstrating completely linearly polarized light emission from excitons and trions in few-layer phosphorene. The implications of the extraordinarily large trion binding energy in a higher-than-one-dimensional material are far-reaching. It provides a room-temperature 2D platform to observe the fundamental many-body interactions in the quasi-1D region.