Batyrev IG, McMahon WE, Zhang SB, Olson JM, Wei SH. Step structures on III-V phosphide (001) surfaces: how do steps and Sb affect CuPt ordering of GaInP2?
PHYSICAL REVIEW LETTERS 2005;
94:096101. [PMID:
15783978 DOI:
10.1103/physrevlett.94.096101]
[Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/14/2004] [Indexed: 05/24/2023]
Abstract
The observation of III-V phosphide (001)-(2 x 2) surfaces makes it possible to solve a long standing mystery of step structures. First-principles calculations show that a bulklike type-B step on a hydrogenated 2 x 2 surface is more stable than a rebonded one by 1.1 eV/unit step. In contrast, this energy difference for a H-free beta(2 x 4) surface is only 0.5 eV/unit step. The large difference explains why the CuPt ordering of GaInP is stronger in metal-organic chemical vapor deposition than in molecular beam epitaxy. However, a minute amount of Sb will preferentially attach to the 2 x 2 surface steps and induce additional step structures that cause ordering disruption.
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