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Title: Exceptional Optoelectronic Properties of Hydrogenated Bilayer Silicene

Silicon is arguably the best electronic material, but not as good an optoelectronic material. By employing first-principles calculations and the cluster-expansion approach, we discover that hydrogenated bilayer silicene (BS) shows promising potential as a new kind of optoelectronic material. Most significantly, hydrogenation converts the intrinsic BS, a strongly indirect semiconductor, into a direct-gap semiconductor with a widely tunable bandgap. At low hydrogen concentrations, four ground states of single- and double-side hydrogenated BS are characterized with dipole-allowed direct (or quasidirect) bandgaps in the desirable range from 1 to 1.5 eV, suitable for solar applications. At high hydrogen concentrations, three well-ordered double-side hydrogenated BS structures exhibit direct (or quasidirect) bandgaps in the color range of red, green, and blue, affording white light-emitting diodes. Our findings open opportunities to search for new silicon-based light-absorption and light-emitting materials for earth-abundant, high-efficiency, optoelectronic applications.
 [1] ;  [1] ;  [1] ;  [2] ;  [2] ;  [3] ;  [4] ;  [1]
  1. ORNL
  2. National Renewable Energy Laboratory (NREL)
  3. University of Utah
  4. Konkuk University, South Korea
Publication Date:
OSTI Identifier:
DOE Contract Number:
Resource Type:
Journal Article
Resource Relation:
Journal Name: Physical Review X; Journal Volume: 4; Journal Issue: 2
Research Org:
Oak Ridge National Laboratory (ORNL); Center for Nanophase Materials Sciences (CNMS)
Sponsoring Org:
SC USDOE - Office of Science (SC)
Country of Publication:
United States