由曲率诱导的带隙波动产生带电激励子 在结构上无序的二维半导体中
Bong Gyu Shin1,2,3, Hye Min Oh4, Jung Jun Bae3
1Department of Nano Science and Technology, Sungkyunkwan University (SKKU), Suwon 16419, Republic of Korea.
ACS nano
|March 29, 2024
概括
像MoS2这样的二维材料中的随机曲率会影响激子的形成. 微观曲应变增强支持区域的局部带电激子 (三子),影响光发光强度.
科学领域:
- 材料科学 材料科学 材料科学
- 凝聚物质物理学 凝聚物质物理学
- 纳米技术纳米技术
背景情况:
- 二维 (2D) 材料具有固有的灵活性,使曲率成为影响其物理性能的重要因素.
- 结构障碍,特别是随机曲率对2D半导体激子行为的影响仍然不完全理解.
研究的目的:
- 研究在二氧化 (SiO2) 上的单层二硫化物 (MoS2) 中的结构障碍和激励子形成之间的关系.
- 阐明随机曲率和曲应变如何影响刺激子的特性,特别是局部带电刺激子 (三子).
主要方法:
- 利用光发光 (PL) 和拉曼光谱来探测结构障碍对单层MoS2.2的影响.
- 分析了基板支和悬浮区域之间的相关性,以区分曲应变的影响.
主要成果:
- 曲率诱导的电荷局部化和带隙波动促进局部充电激子 (三子) 的形成.
- 在基板支的区域中,由于随机曲应变的局部电荷,trion数量得到增强,但在悬浮区域中被抑制.
- 光发光强度显示支持和悬浮区域之间的显著变化 (高达100倍),归因于通过曲应变的刺激再分配.
- 观察到PL峰位和拉曼E峰位之间的反向关系,证实了曲应变和PL之间的相关性.
结论:
- 结构障碍,特别是随机曲率和曲应变,在像MoS2.2这样的二维半导体中调节激子形成和光发光度方面发挥着至关重要的作用.
- 这些发现为推进2D材料的光电子和应变工程应用提供了基本的见解.
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