arXivDaily arXiv每日学术速递 周一至周五更新
arXiv 2001.07308cond-mat.mtrl-sci
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ReS2中堆垛阶驱动的光学性质和载流子动力学

Stacking Order Driven Optical Properties and Carrier Dynamics in ReS2

Yongjian Zhou, Nikhilesh Maity, Amritesh Rai, Rinkle Juneja, Xianghai Meng, Anupam Roy, Xiaochuan Xu, Jung-Fu Lin, Sanjay Banerjee, Abhishek K. Singh, Yaguo Wang

摘要:

两个不同的堆叠顺序ReS 2确定没有歧义和振动,光学性质和载流子动力学的影响进行了研究。与原子分辨率扫描透射电子显微镜(STEM),两个堆叠顺序被确定为AA堆叠与跨层的位移可以忽略不计,和AB堆叠与约一个单元格沿a轴的位移。第一性原理计算证实,这两个堆叠顺序对应于两个本地的能量最小值。拉曼光谱告知模式I和III的一致差异,AA堆叠约为13 cm-1,AB堆叠约为20 cm-1,这是确定ReS 2中堆叠顺序的简单工具。偏振光致发光(PL)显示,AB堆叠具有蓝移的PL峰位,和更宽的峰宽度,相比AA堆叠,表明更强的层间相互作用。飞秒泵浦探测光谱测量的瞬态透射表明,在AB堆叠中激子动力学更各向异性,其中当探测偏振垂直于b轴对齐时,与Exc. III模式相关的激发态吸收消失。我们的研究结果强调了ReS 2的堆叠顺序驱动的光学特性和载流子动力学,调解了文献中许多看似矛盾的结果,并开辟了一个机会,通过操纵堆叠顺序来设计具有新功能的电子器件。

英文摘要:

Two distinct stacking orders in ReS2 are identified without ambiguity and their influence on vibrational, optical properties and carrier dynamics are investigated. With atomic resolution scanning transmission electron microscopy (STEM), two stacking orders are determined as AA stacking with negligible displacement across layers, and AB stacking with about a one-unit cell displacement along the a axis. First-principle calculations confirm that these two stacking orders correspond to two local energy minima. Raman spectra inform a consistent difference of modes I & III, about 13 cm-1 for AA stacking, and 20 cm-1 for AB stacking, making a simple tool for determining the stacking orders in ReS2. Polarized photoluminescence (PL) reveals that AB stacking possesses blue-shifted PL peak positions, and broader peak widths, compared with AA stacking, indicating stronger interlayer interaction. Transient transmission measured with femtosecond pump probe spectroscopy suggests exciton dynamics being more anisotropic in AB stacking, where excited state absorption related to Exc. III mode disappears when probe polarization aligns perpendicular to b axis. Our findings underscore the stacking-order driven optical properties and carrier dynamics of ReS2, mediate many seemingly contradictory results in literature, and open up an opportunity to engineer electronic devices with new functionalities by manipulating the stacking order.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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