Applicability study of the structure-factor phase method for determining the polarity of binary semiconductors

Area of Science:

• Materials Science
• Solid-State Physics
• Crystallography

Background:

• Convergent-beam electron diffraction (CBED) is a key technique for analyzing crystal structures.
• The structure-factor phase method is established for determining the polarity of binary compound materials like GaAs.
• The applicability of this method to diverse polar materials remains underexplored.

Purpose of the Study:

• To investigate the potential applicability of the structure-factor phase method in convergent-beam electron diffraction (CBED) for various AB-type polar semiconductors.
• To identify critical factors influencing the method's accuracy in polarity determination.
• To assess the limitations of the CBED method for different crystal structures.

Main Methods:

• Extensive dynamical simulations of CBED were performed on 11 AB-type semiconductors.
• The influence of the atomic number difference between constituent atoms (A and B) was analyzed.
• The effect of sample thickness on the simulation results was systematically investigated.

Main Results:

• The structure-factor phase method proves efficient for determining the polarity of sphalerite semiconductor structures under specific conditions.
• The method's effectiveness is significantly limited when applied to wurtzite semiconductor structures.
• Simulation parameters such as atomic number differences and sample thickness critically impact polarity determination accuracy.

Conclusions:

• The CBED structure-factor phase method is a viable tool for sphalerite polarity determination, contingent on specific simulation parameters.
• The method shows limited utility for polarity determination in wurtzite structures, despite their structural similarity to sphalerites.
• Further research is needed to adapt or develop alternative methods for reliable polarity determination in wurtzite materials.