Platelike structures of semiconductor clusters Ge(n) (n = 40-44)

Area of Science:

• Computational materials science
• Quantum chemistry
• Solid-state physics

Background:

• Understanding the structural properties of germanium clusters is crucial for developing new semiconductor materials.
• Previous studies have explored smaller germanium clusters, but the structural preferences of medium-sized clusters (n=40-44) remain less understood.

Purpose of the Study:

• To determine the most stable structural configurations of germanium clusters with sizes ranging from 40 to 44 atoms (Ge(n), n=40-44).
• To investigate the electronic and geometric properties of these clusters using advanced computational methods.
• To compare theoretical findings with experimental data, specifically cluster mobilities.

Main Methods:

• A genetic algorithm was employed in conjunction with a tight-binding method to search for potential cluster structures.
• First-principles calculations based on density functional theory (DFT) were utilized for further optimization of the identified isomer structures.
• Cluster mobilities were calculated for the most stable structures and compared with experimental measurements.

Main Results:

• Germanium clusters (Ge(n), n=40-44) predominantly adopt platelike structures.
• These stable structures are characterized by a central Ge(4) core, which is integrated with four smaller magic clusters (Ge(9) or Ge(10)).
• The calculated cluster mobilities for the optimized structures show good agreement with existing experimental data.

Conclusions:

• The study successfully identified the favored platelike structures for Ge(n) (n=40-44) clusters.
• The combination of genetic algorithm and DFT provides a reliable approach for predicting cluster structures.
• The agreement between calculated and experimental mobilities validates the proposed structural models for germanium clusters.