Elucidating the Degradation Mechanisms in Silicon Telluride through Multimodal Characterization
Elucidating the Degradation Mechanisms in Silicon Telluride through Multimodal Characterization
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DOI：
10.1021/acs.jpcc.3c01864
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发表时间：
2023-07-05
影响因子：
3.7
通讯作者：
Cui，Jingbiao
中科院分区：
文献类型：
--
作者：
Hathaway，Evan;Rodriguez，Roberto Gonzalez;Cui，Jingbiao
随着时间的推移，碲化硅(Si2Te3)和许多其他含碲化合物在∼120和∼140 cm-1处都有明显的拉曼峰。这两个峰的起源在文献中一直存在争议，并被归因于多种原因，如碲化物材料的本征拉曼模式、表面氧化、缺陷、双共振和碲的沉淀。这些峰的争议性导致高度降解的物质被误认为是原始的，并导致对拉曼光谱变化的误解。在这里，我们对化学气相沉积生长的Si2Te3薄膜和大块晶体进行了全面和多峰的研究。我们发现这两个拉曼峰来自于退化的Si2Te3表面层中形成的碲纳米晶。碲纳米晶的形成被证明是Si2Te3与大气水蒸气反应的水解过程的结果。这项研究明确地澄清了许多碲化物化合物中有争议的拉曼峰的来源，并为未来对这些材料体系的准确表征提供了蓝图。
Silicon telluride (Si2Te3) and many other tellurium-containing compounds show emergent Raman peaks located at ∼120 and ∼140 cm–1as they age. The origin of these two emergent peaks is controversial in the literature and has been attributed to myriad causes such as the intrinsic Raman modes of the telluride materials, surface oxidation, defects, double resonances, and tellurium precipitates. The controversial nature of these peaks has led to the misidentification of highly degraded materials as pristine and to the misinterpretation of changes in Raman spectra. Here, we present a comprehensive and multimodal study on Si2Te3thin films and bulk crystals grown by a chemical vapor deposition process. We find that the two emergent Raman peaks originate from tellurium nanocrystallites formed in the degraded surface layers of Si2Te3. The formation of the tellurium nanocrystallites is shown to be a result of a hydrolysis process in which Si2Te3reacts with atmospheric water vapor. This study unambiguously clarifies the origin of the controversial Raman peaks seen in numerous telluride compounds and provides a blueprint for the accurate characterization of these material systems in the future.