Electronic structure of Humble defects in Ge and Ge$_{0.8}$Si$_{0.2}$

التفاصيل البيبلوغرافية
العنوان: Electronic structure of Humble defects in Ge and Ge$_{0.8}$Si$_{0.2}$
المؤلفون: Ren, Shang, Yang, Hongbin, Singh, Sobhit, Batson, Philip E., Garfunkel, Eric L., Vanderbilt, David
سنة النشر: 2022
المجموعة: Condensed Matter
مصطلحات موضوعية: Condensed Matter - Materials Science, Condensed Matter - Mesoscale and Nanoscale Physics
الوصف: The group-IV diamond-structure elements are known to host a variety of planar defects, including {001} planar defects in C and {001}, {111} and {113} planar defects in Si and Ge. Among the {001} planar defects, the Humble defect, known for some time to occur in Ge, has recently also been observed in Si/Ge alloys, but the details of its electronic structure remain poorly understood. Here we perform first-principles density functional calculations to study Humble defects in both Ge and Ge$_{0.8}$Si$_{0.2}$. We also measure the Si L$_{2,3}$-edge electron energy loss spectra both at the defect and in a bulk-like region far from the defect, and compare with theoretical calculations on corresponding Si sites in our first-principles calculations. We find that inclusion of core-hole effects in the theory is essential for reproducing the observed L$_{2,3}$ edge spectra, and that once they are included, the results provide a set of fingerprints for different types of local atomic bonding environments in Ge$_{0.8}$Si$_{0.2}$. Our first-principles calculations reveal that the Humble defects have a tendency to enlarge the electronic band gap, which may have potential uses in band engineering. The use of hybrid functionals for an improved description of the band gap in these systems is also discussed.
Comment: 11 pages, 10 figures; Comments are welcome
نوع الوثيقة: Working Paper
DOI: 10.1103/PhysRevB.106.155302
URL الوصول: http://arxiv.org/abs/2206.13726
رقم الانضمام: edsarx.2206.13726
قاعدة البيانات: arXiv
الوصف
DOI:10.1103/PhysRevB.106.155302