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arXiv · 2402.18833

Layer-dependent Raman spectroscopy of ultrathin Ta$_2$Pd$_3$Te$_5$

Zhenyu Sun·Zhaopeng Guo·Dayu Yan·Peng Cheng·Lan Chen·Youguo Shi·Yuan Huang·Zhijun Wang·Kehui Wu·Baojie Feng
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Abstract

Two-dimensional topological insulators (2DTIs) or quantum spin Hall insulators are attracting increasing attention due to their potential applications in next-generation spintronic devices. Despite their promising prospects, realizable 2DTIs are still limited. Recently, Ta2Pd3Te5, a semiconducting van der Waals material, has shown spectroscopic evidence of quantum spin Hall states. However, achieving controlled preparation of few- to monolayer samples, a crucial step in realizing quantum spin Hall devices, has not yet been achieved. In this work, we fabricated few- to monolayer Ta$_2$Pd$_3$Te$_5$ and performed systematic thickness- and temperature-dependent Raman spectroscopy measurements. Our results demonstrate that Raman spectra can provide valuable information to determine the thickness of Ta2Pd3Te5 thin flakes. Moreover, our angle-resolved polarized Raman (ARPR) spectroscopy measurements show that the intensities of the Raman peaks are strongly anisotropic due to the quasi-one-dimensional atomic structure, providing a straightforward method to determine its crystalline orientation. Our findings may stimulate further efforts to realize quantum devices based on few or monolayer Ta$_2$Pd$_3$Te$_5$.

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Zhenyu Sun, Zhaopeng Guo, Dayu Yan, Peng Cheng, Lan Chen, Youguo Shi, Yuan Huang, Zhijun Wang, Kehui Wu, Baojie Feng. 2024-02-29. Layer-dependent Raman spectroscopy of ultrathin Ta$_2$Pd$_3$Te$_5$. https://doi.org/10.1103/physrevmaterials.7.094004

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