The emission properties of GeSn heterostructure pin diodes have been investigated. The devices contain thick (400–600 nm) Ge1-y Sny i-layers spanning a broad compositional range below and above the crossover Sn concentration yc where the Ge1-y Sny alloy becomes a direct-gap material. These results are made possible by an optimized device architecture containing a single defected interface thereby mitigating the deleterious effects of mismatch-induced defects. The observed emission intensities as a function of composition show the contributions from two separate trends: an increase in direct gap emission as the Sn concentration is increased, as expected from the reduction and eventual reversal of the separation between the direct and indirect edges, and a parallel increase in non-radiative recombination when the mismatch strains between the structure components is partially relaxed by the generation of misfit dislocations. An estimation of recombination times based on the observed electroluminescence intensities is found to be strongly correlated with the reverse-bias dark current measured in the same devices.
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- Electroluminescence From GeSn Heterostructure Pin Diodes at the Indirect to Direct Transition
- Gallagher, J. D. (Author)
- Senaratne, Charutha Lasitha (Author)
- Sims, Patrick (Author)
- Aoki, Toshihiro (Author)
- Menéndez, Jose (Author)
- Kouvetakis, John (Author)
- College of Liberal Arts and Sciences (Contributor)
- Digital object identifier: 10.1063/1.4913688
- Identifier TypeInternational standard serial numberIdentifier Value0003-6951
- Identifier TypeInternational standard serial numberIdentifier Value1077-3118
- Copyright 2015 American Institute of Physics. This article may be downloaded for personal use only. Any other use requires prior permission of the author and the American Institute of Physics. along with the following message: The following article appeared in APPLIED PHYSICS LETTERS 106, 091103 (2015) and may be found at http://dx.doi.org/10.1063/1.4913688
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Gallagher, J. D., Senaratne, C. L., Sims, P., Aoki, T., Menendez, J., & Kouvetakis, J. (2015). Electroluminescence from GeSn heterostructure pin diodes at the indirect to direct transition. APPLIED PHYSICS LETTERS, 106, 091103. http://dx.doi.org/10.1063/1.4913688