Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
9567310 | Applied Surface Science | 2005 | 4 Pages |
Abstract
Structural stability of GaNxAs1âx thin films coherently grown on GaAs(1 1 1) is systematically investigated based on an empirical potential, which incorporates electrostatic energies due to bond charges and ionic charges. Using the empirical potential, the system energies of zinc blende (ZB) and wurtzite (W) structured GaNxAs1âx thin films are calculated over the entire concentration range. The calculated results predict that the structural phase transition from ZB to W occurs at xc â¼Â 0.5, which differs from xc â¼Â 0.7 expected by the electrostatic energy contribution dominating W-ZB polytypism in end members such as GaN and GaAs. The difference between the values of xc is clarified in terms of difference in bond lengths distribution in ZB-GaNxAs1âx and W-GaNxAs1âx. Further calculations for interface structures between ZB- or W-GaNxAs1âx thin films and GaAs(1 1 1) substrate reveal that ZB-type stacking sequence is more favorable than W-type stacking sequence at the interface. Consequently, ZB-GaNxAs1âx thin films can be fabricated in the concentration range of x < 0.5 on the GaAs(1 1 1), whereas W-GaNxAs1âx thin films are formed with ZB-type stacking interface in the concentration range of x â¥Â 0.5.
Related Topics
Physical Sciences and Engineering
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Physical and Theoretical Chemistry
Authors
Tomonori Ito, Takashi Suda, Toru Akiyama, Kohji Nakamura,