The formation of a Sn monolayer on Ge(1 0 0) studied at the atomic scale
| Autor: | Taylor J. Z. Stock, Wolfgang M. Klesse, Francesco Montalenti, Neil J. Curson, Emilio Scalise, Steven R. Schofield, Emily V.S. Hofmann, Leo Miglio, Giovanni Capellini |
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| Přispěvatelé: | Hofmann, E. V. S., Scalise, E., Montalenti, F., Stock, T. J. Z., Schofield, S. R., Capellini, G., Miglio, L., Curson, N. J., Klesse, W. M., Hofmann, E, Scalise, E, Montalenti, F, Stock, T, Schofield, S, Capellini, G, Miglio, L, Curson, N, Klesse, W |
| Rok vydání: | 2021 |
| Předmět: |
Materials science
STM General Physics and Astronomy 02 engineering and technology 010402 general chemistry DFT 01 natural sciences Atomic units Wetting layer law.invention law Monolayer FIS/03 - FISICA DELLA MATERIA Quantum well Deposition (law) Surfaces and Interfaces General Chemistry 021001 nanoscience & nanotechnology Condensed Matter Physics 0104 chemical sciences Surfaces Coatings and Films GeSn Chemical physics Density functional theory Scanning tunneling microscope 0210 nano-technology Layer (electronics) |
| Zdroj: | Applied Surface Science. 561:149961 |
| ISSN: | 0169-4332 |
| DOI: | 10.1016/j.apsusc.2021.149961 |
| Popis: | The growth of multi-layer germanium-tin (GeSn) quantum wells offers an intriguing pathway towards the integration of lasers in a CMOS platform. An important step in growing high quality quantum well interfaces is the formation of an initial wetting layer. However, key atomic-scale details of this process have not previously been discussed. We use scanning tunneling microscopy combined with density functional theory to study the deposition of Sn on Ge(1 0 0) at room temperature over a coverage range of 0.01 to 1.24 monolayers. We demonstrate the formation of a sub-2% Ge content GeSn wetting layer from three atomic-scale characteristic ad-dimer structural components, and show that small quantities of Sn incorporate into the Ge surface forming two atomic configurations. The ratio of the ad-dimer structures changes with increasing Sn coverage, indicating a change in growth kinetics. At sub-monolayer coverage, the least densely packing ad-dimer structure is most abundant. As the layer closes, forming a two-dimensional wetting layer, the more densely packing ad-dimer structure become dominant. These results demonstrate the capability to form an atomically smooth wetting layer at room temperature, and provide critical atomic-scale insights for the optimization of growth processes of GeSn multi-quantum-wells to meet the quality requirements of optical GeSn-based devices. |
| Databáze: | OpenAIRE |
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