| Autor: |
Gallagher, J. D., Xu, C., Senaratne, C. L., Aoki, T., Wallace, P. M., Kouvetakis, J., Menéndez, J. |
| Předmět: |
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| Zdroj: |
Journal of Applied Physics; 10/7/2015, Vol. 118 Issue 13, p135701-1-135701-6, 6p, 1 Diagram, 5 Graphs |
| Abstrakt: |
This paper reports initial the demonstration of prototype Ge1–x–ySixSny light emitting diodes with distinct direct and indirect edges and high quality I-V characteristics. The devices are fabricated on Si (100) wafers in heterostructure pin geometry [n-Ge/i-Ge1–x–ySixSny/p-Ge(Sn/Si)] using ultra low-temperature (T<300 °C) depositions of the highly reactive chemical sources Si4H10, Ge4H10, Ge3H8, and SnD4. The Sn content in the i-Ge1–x–ySixSny layer was varied from ~3.5% to 11%, while the Si content was kept constant near 3%. The Si/Sn amounts in the p-layer were selected to mitigate the lattice mismatch so that the top interface grows defect-free, thereby reducing the deleterious effects of mismatch-induced dislocations on the optical/electrical properties. The spectral responsivity plots of the devices reveal sharp and well-defined absorption edges that systematically red-shift in the mid-IR from 1750 to 2100 nm with increasing Sn content from 3.5% to 11%. The electroluminescence spectra reveal strong direct-gap emission peaks and weak lower energy shoulders attributed to indirect gaps. Both peaks in a given spectrum red-shift with increasing Sn content and their separation decreases as the material approaches direct gap conditions in analogy with binary Ge1–ySny counterparts. These findings-combined with the enhanced thermal stability of Ge1–x–ySixSny relative to Ge1–ySny and the observation that ternary alloy disorder does not adversely affect the emission properties—indicate that Ge1–x–ySixSny may represent a practical target system for future generations of group-IV light sources on Si. [ABSTRACT FROM AUTHOR] |
| Databáze: |
Complementary Index |
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