Temperature dependence of the dielectric function and interband transitions of pseudomorphic GeSn alloys
| Autor: | Wei Wang, Daniel Schmidt, Yee-Chia Yeo, Vijay Richard D'Costa |
|---|---|
| Rok vydání: | 2016 |
| Předmět: |
010302 applied physics
Materials science Condensed matter physics Phonon Process Chemistry and Technology Semiconductor materials 02 engineering and technology Dielectric 021001 nanoscience & nanotechnology 01 natural sciences Surfaces Coatings and Films Electronic Optical and Magnetic Materials law.invention Germanium compounds law 0103 physical sciences Materials Chemistry Empirical formula Spectroscopic ellipsometry Dielectric function Electrical and Electronic Engineering 0210 nano-technology Instrumentation Bose–Einstein condensate |
| Zdroj: | Journal of Vacuum Science & Technology B, Nanotechnology and Microelectronics: Materials, Processing, Measurement, and Phenomena. 34:041204 |
| ISSN: | 2166-2754 2166-2746 |
| DOI: | 10.1116/1.4946759 |
| Popis: | The authors investigated the temperature dependence of the complex dielectric function and interband transitions of pseudomorphic Ge1−xSnx (x = 0, 0.025, and 0.075) alloys using spectroscopic ellipsometry from 77 to 400 K. The dielectric functions and interband transitions of the alloys blue-shift with decreasing temperature. The dependence of E1, E1 + Δ1, and E2 transitions on temperature can be represented by either Varshni's empirical formula or an expression proportional to the Bose–Einstein statistical factor of an average phonon. The authors find that the temperature-dependence is similar to that of bulk Ge with the exception of an offset accounting for the alloying of α-Sn into Ge. In addition, the temperature-dependent E1 and E1 + Δ1 transition energies in pseudomorphic GeSn alloys can be predicted by combining their room-temperature compositional dependencies with the energy shifts resulting from the temperature dependence of these transitions in Ge. |
| Databáze: | OpenAIRE |
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