Wang Peng-Jui, Yang Zih-Sian, Chang Che-Jia, Lin Shih-Yen, Sun Chi-Kuang
Department of Electrical Engineering and Graduate Institute of Photonics and Optoelectronics, National Taiwan University, Taipei 10617, Taiwan.
Graduate Institute of Electronics Engineering, National Taiwan University, No. 1, Sec. 4, Roosevelt Rd., Taipei 10617, Taiwan.
J Chem Phys. 2024 Sep 7;161(9). doi: 10.1063/5.0216616.
Antimonene, a promising conductor for next-generation 2D-based devices, has its contact resistance significantly influenced by the van der Waals (vdW) interaction within its heterostructure. In this study, we report the quantification of the vdW coupling between multilayer antimonene and bilayer MoS2 by ultrafast coherent vibration spectroscopy. By utilizing a femtosecond laser, we excited coherent acoustic vibrations in the multilayer-antimonene on substrate-supported bilayer MoS2, and the relative displacement at the vdW heterojunction was detected with the aid of bilayer MoS2. The photoexcited strain pulse generated in the multilayer-antimonene was observed as it transported to the bilayer MoS2, explaining the distortion at the beginning of the oscillation. By analyzing the thickness-dependent oscillation frequencies, we determine the effective vdW elastic constant between multilayer-antimonene and MoS2 to be (1.9 ± 0.2) × 1018 N/m3. This non-destructive optical technique offers a significant advance in the evaluation of vdW interactions at 2D metal-semiconductor interfaces.
锑烯是一种很有前景的用于下一代二维器件的导体，其接触电阻会受到异质结构内范德华（vdW）相互作用的显著影响。在本研究中，我们通过超快相干振动光谱法报告了多层锑烯与双层二硫化钼（MoS2）之间范德华耦合的量化情况。利用飞秒激光，我们在衬底支撑的双层MoS2上的多层锑烯中激发了相干声振动，并借助双层MoS2检测了范德华异质结处的相对位移。当光激发应变脉冲从多层锑烯传输到双层MoS2时被观察到，这解释了振荡开始时的畸变现象。通过分析与厚度相关的振荡频率，我们确定多层锑烯与MoS2之间的有效范德华弹性常数为(1.9 ± 0.2) × 1018 N/m3。这种无损光学技术在评估二维金属 - 半导体界面处的范德华相互作用方面取得了重大进展。
