Spectroscopic ellipsometry as an in-situ monitoring tool for Bi2Se3 films grown by molecular beam epitaxy
| Autor: | Phoebe Killea, Roman Engel-Herbert, Maria Hilse, Xiaoyu Wang, Frank Peiris |
|---|---|
| Rok vydání: | 2021 |
| Předmět: |
010302 applied physics
Materials science business.industry Heterojunction 02 engineering and technology Substrate (electronics) Dielectric 021001 nanoscience & nanotechnology Condensed Matter Physics 01 natural sciences Spectral line Inorganic Chemistry Condensed Matter::Materials Science Topological insulator 0103 physical sciences Materials Chemistry Sapphire Optoelectronics Growth rate 0210 nano-technology business Molecular beam epitaxy |
| Zdroj: | Journal of Crystal Growth. :126177 |
| ISSN: | 0022-0248 |
| DOI: | 10.1016/j.jcrysgro.2021.126177 |
| Popis: | In-operando spectroscopic ellipsometry (SE) was used to measure the optical response of Bi2Se3 films grown on sapphire substrates in a molecular beam epitaxy (MBE) reactor during cool-down from a growth temperature of 225 °C. A temperature dependent dielectric model was refined for the topological insulator Bi2Se3 by taking SE spectra at different temperatures and fitting the amplitude ratio and phase difference of orthogonally polarized light using Bi2Se3 films with varying thickness. In-operando SE demonstrated here enabled determining the dielectric function of substrate and growing film unobscured by surface or interface reactions. Its sensitivity to sample temperature and film thickness variations allows determining growth temperature, absolute film thickness, and growth rate in real time, rendering it a reliable and universal approach for a direct comparison of growth conditions between different growth campaigns, thus offering the potential to improve reproducibility of the growth conditions for Bi2Se3 based films and heterostructures. |
| Databáze: | OpenAIRE |
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