Une surstructure de α-Ge, type diamant, induite par un dopage d'anti-moine

Area of Science:

• Solid State Chemistry
• Materials Science
• Crystallography

Background:

• Germanium (Ge) is a crucial semiconductor material.
• Doping Ge with antimony (Sb) can modify its electronic properties.
• Understanding the precise atomic arrangement in doped semiconductors is vital for device performance.

Purpose of the Study:

• To synthesize and characterize single crystals of antimony-doped germanium.
• To elucidate the crystallographic structure and atomic positions of antimony within the germanium lattice.
• To investigate the bonding characteristics and potential mobility of antimony atoms.

Main Methods:

• Single crystal growth using chemical transport reaction.
• X-ray diffraction analysis to determine crystallographic structure.
• Structural modeling to refine atomic positions and occupancies.

Main Results:

• Antimony-doped germanium (Ge₁₋ₓSbₓ, x ≃ 0.0625) single crystals were successfully grown.
• The alloy forms a superstructure of the diamond-type α-Ge.
• Antimony atoms were found to occupy germanium lattice sites (4a) and adjacent tetrahedral interstitial sites (4c/4d) with partial occupancy (16%).

Conclusions:

• The crystal structure features strong covalent bonds.
• No close antimony-antimony contacts were observed.
• The interstitial antimony atoms are suggested to be mobile, moving between adjacent tetrahedral sites.