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Title: Properties of the exotic metastable ST12 germanium allotrope

Journal Article · · Nature Communications
DOI:https://doi.org/10.1038/ncomms13909· OSTI ID:1345973
 [1];  [2];  [3];  [4];  [2];  [2]
  1. Carnegie Institution of Washington, Washington, D.C. (United States); Yanshan Univ., Qinhuangdao (China)
  2. Carnegie Institution of Washington, Washington, D.C. (United States)
  3. Carnegie Institution of Washington, Washington, D.C. (United States); Center for High Pressure Science and Technology Advanced Research, Shanghai (China)
  4. Yanshan Univ., Qinhuangdao (China)

The optical and electronic properties of semiconducting materials are of great importance to a vast range of contemporary technologies. Diamond-cubic germanium is a well-known semiconductor, although other ‘exotic’ forms may possess distinct properties. In particular, there is currently no consensus for the band gap and electronic structure of ST12-Ge (tP12, P43212) due to experimental limitations in sample preparation and varying theoretical predictions. Here we report clear experimental and theoretical evidence for the intrinsic properties of ST12-Ge, including the first optical measurements on bulk samples. Phase-pure bulk samples of ST12-Ge were synthesized, and the structure and purity were verified using powder X-ray diffraction, transmission electron microscopy, Raman and wavelength/energy dispersive X-ray spectroscopy. Lastly, optical measurements indicate that ST12-Ge is a semiconductor with an indirect band gap of 0.59 eV and a direct optical transition at 0.74 eV, which is in good agreement with electrical transport measurements and our first-principles calculations.

Research Organization:
Carnegie Institution of Washington, Washington, D.C. (United States); Energy Frontier Research Centers (EFRC) (United States). Energy Frontier Research in Extreme Environments (EFree)
Sponsoring Organization:
USDOE Office of Science (SC), Basic Energy Sciences (BES)
Grant/Contract Number:
SC0001057
OSTI ID:
1345973
Journal Information:
Nature Communications, Vol. 8; ISSN 2041-1723
Publisher:
Nature Publishing GroupCopyright Statement
Country of Publication:
United States
Language:
English
Citation Metrics:
Cited by: 30 works
Citation information provided by
Web of Science

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Physical properties of group 14 semiconductor alloys in orthorhombic phase journal July 2019
Optical properties and lattice dynamics of a novel allotrope of orthorhombic elemental germanium journal February 2019
Physical properties of Si–Ge alloys in C 2/ m phase: a comprehensive investigation journal April 2019
Complex Low Energy Tetrahedral Polymorphs of Group IV Elements from First Principles journal October 2018
Zintl Phases as Reactive Precursors for Synthesis of Novel Silicon and Germanium-Based Materials journal April 2019
Complex Low Energy Tetrahedral Polymorphs of Group IV Elements from First Principles. text January 2018