
Silicene, a two-dimensional form of silicon, has attracted significant interest for its potential in advanced technologies. Like graphene, it has a unique structure that allows electrons to move in interesting ways, making it highly compatible with existing semiconductor technologies. However, despite progress in creating and working with silicene, challenges remain—especially in finding suitable surfaces (substrates) to support its structure. For instance, scientists often use a silver surface to grow silicene, and adding a layer of another material, such as stanene, can help reduce interactions between silicene and silver. Understanding how silicene interacts with these layers is crucial for turning it into functional devices.
Key parameters of novel materials include electrical and thermal conductivity, but silicene’s thermal behavior at the ultra-thin (2D) level remains unexplored. So far, studies on silicene’s thermal conductivity are mostly theoretical, with a wide range of predicted values: from 9 to 40 W/mK (watts per meter-kelvin), depending on the computational methods employed. Experiments on silicene's thermal properties are rare due to difficulties in creating suitable test setups.Â
A collaborative effort between the Semiconductors Spectroscopy Lab (LASSEM) of the Department of Materials Science, Università degli Studi di Milano-Bicocca (E. Bonaventura, J. Pedrini, F. Pezzoli, E. Bonera) and CNR IMM– Agrate Unit (D. S. Dhungana, C. Massetti, C. Grazianetti, C. Martella, A. Molle) has made progress to fill this knowledge gap. Utilizing a technique called optothermal Raman spectroscopy, the team investigated how silicene conducts heat when supported by different materials. The study examined two configurations: silicene directly on silver and silicene on a stanene buffer layer. This approach uses laser light to simultaneously heat the material and monitor how  temperature variations affect its Raman spectrum - a type of unique "fingerprint" for materials. By analyzing these spectral changes, the researchers successfully quantified silicene's thermal conductivity.
This study highlights how different configurations of silicene can reveal critical thermal and electrical properties, helping to bridge the gap between theoretical predictions and real-world applications. These findings are pivotal for the development of advanced thermoelectric and electronic devices incorporating silicene.
The results are reported in the paper  “Effective Out-Of-Plane Thermal Conductivity of Silicene by Optothermal Raman Spectroscopy" (DOI: 10.1002/adom.202401466) published on Advanced Optical Materials (Impact Factor 8.0 – Wiley 2024).
The article is published with Creative Commons Attribution 4.0.