التفاصيل البيبلوغرافية
| العنوان: |
Local ordering in Ge/Ge–Sn semiconductor alloy core/shell nanowires revealed by extended x-ray absorption fine structure (EXAFS). |
| المؤلفون: |
Lentz, J. Zach1 (AUTHOR), Woicik, J. C.2 (AUTHOR), Bergschneider, Matthew3 (AUTHOR), Davis, Ryan4 (AUTHOR), Mehta, Apurva5 (AUTHOR), Cho, Kyeongjae3 (AUTHOR), McIntyre, Paul C.1,4 (AUTHOR) pcm1@slac.stanford.edu |
| المصدر: |
Applied Physics Letters. 2/6/2023, Vol. 122 Issue 6, p1-7. 7p. |
| مصطلحات موضوعية: |
*EXTENDED X-ray absorption fine structure, *NANOWIRES, *SEMICONDUCTOR nanowires, *ALLOYS, *SEMICONDUCTORS |
| مستخلص: |
Short-range atomic order in semiconductor alloys is a relatively unexplored topic that may promote design of new materials with unexpected properties. Here, local atomic ordering is investigated in Ge–Sn alloys, a group-IV system that is attractive for its enhanced optoelectronic properties achievable via a direct gap for Sn concentrations exceeding ≈10 at. %. The substantial misfit strain imposed on Ge–Sn thin films during growth on bulk Si or Ge substrates can induce defect formation; however, misfit strain can be accommodated by growing Ge–Sn alloy films on Ge nanowires, which effectively act as elastically compliant substrates. In this work, Ge core/Ge1−xSnx (x ≈ 0.1) shell nanowires were characterized with extended x-ray absorption fine structure (EXAFS) to elucidate their local atomic environment. Simultaneous fitting of high-quality EXAFS data collected at both the Ge K-edge and the Sn K-edge reveals a large (≈ 40%) deficiency of Sn in the first coordination shell around a Sn atom relative to a random alloy, thereby providing the first direct experimental evidence of significant short-range order in this semiconductor alloy system. Comparison of path length data from the EXAFS measurements with density functional theory simulations provides alloy atomic structures consistent with this conclusion. [ABSTRACT FROM AUTHOR] |
| قاعدة البيانات: |
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