Luminescence of strained Ge on GeSn virtual substrate grown on Si (001)
| Autor: | Martin Kittler, Jörg Schulze, Bernhard Schwartz, Michael Oehme, Stefan Bechler, R. Koerner |
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| Rok vydání: | 2017 |
| Předmět: |
010302 applied physics
Materials science business.industry chemistry.chemical_element Germanium 02 engineering and technology Substrate (electronics) Electroluminescence 021001 nanoscience & nanotechnology 01 natural sciences Active layer law.invention chemistry law 0103 physical sciences Optoelectronics Light emission 0210 nano-technology business Luminescence Molecular beam epitaxy Light-emitting diode |
| Zdroj: | Silicon Photonics XII. |
| ISSN: | 0277-786X |
| DOI: | 10.1117/12.2249564 |
| Popis: | To enlarge the tensile strain in Ge light emission diodes (s-Ge LED) we applied a GeSn virtual substrate (VS) on Si (001) with a Sn content of 4.5 %, to produce s-Ge LEDs. The LED stack was grown by molecular beam epitaxy. Electroluminescence investigations of the s-Ge LED show a major direct Ge peak and a minor peak at lower energy, which is formed by the GeSn-VS and the s-Ge indirect transition. The main peak of a 100 nm thick s-Ge LED is red-shifted as compared to the Ge peak of an unstrained reference Ge LED grown on Ge-VS. At a temperature of T = 80 K the increased tensile strain, produced by the GeSn-VS, causes a redshift of the direct Ge peak from 0.809 eV to 0.745 and 0.769 eV, namely for the s-Ge LED with a 100 and 200 nm thick active layer. At T = 300 K the direct Ge peak is shifted from 0.777 eV of the reference Ge LED to 0.725 eV (for 100 nm) and 0.743 eV (for 200 nm). The peak positions do not differ much between the 50 and 100 nm thick s-Ge LEDs. The intensities of the direct Ge peak increase with the s-Ge layer thickness. Moreover, the intensity of the 50 nm thick s-Ge sample is found to be larger than that of the 100 nm thick reference Ge LED. |
| Databáze: | OpenAIRE |
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