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Surface-dependent band structure variations and bond deviations of GaN
Chih-Shan Tan1, Michael H Huang2
1Institute of Electronics, National Yang Ming Chiao Tung University, Hsinchu 300093, Taiwan. cstan@nycu.edu.tw.
Physical Chemistry Chemical Physics : PCCP
|April 11, 2022
Summary
Density functional theory (DFT) reveals that Gallium Nitride (GaN) surface structure depends on crystal facet. Odd-numbered layers of certain GaN facets show bond distortions, impacting electronic properties.
Area of Science:
- Materials Science
- Condensed Matter Physics
- Computational Chemistry
Background:
- Gallium Nitride (GaN) is a crucial semiconductor material.
- Surface properties significantly influence semiconductor device performance.
- Understanding facet-dependent electronic and structural properties is vital.
Purpose of the Study:
- To investigate the impact of tunable layer thickness on GaN electronic band structure.
- To analyze structural variations across different GaN crystallographic planes ((0001), (101̄0), (101̄1)).
- To correlate structural changes with electronic property variations.
Main Methods:
- Density Functional Theory (DFT) calculations were employed.
- Simulations involved varying the number of atomic layers for different GaN facets.
- Analysis focused on band structure, density of states (DOS), band gap, and atomic bond geometry.
Main Results:
- GaN (0001) planes showed invariant electronic properties regardless of layer number.
- GaN (101̄0) and (101̄1) planes exhibited dissimilar band structures and DOS for specific layer counts.
- Odd-numbered layers of GaN (101̄0) and 1-4 layers of GaN (101̄1) showed bond length variations and distortions.
Conclusions:
- Facet-dependent structural deviations occur near the GaN surface.
- These atomic position deviations can lead to observable changes in electronic properties.
- The findings are relevant for understanding surface effects in various semiconductor materials.
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