First-Principles Surface Phase Diagram for Hydrogen on GaN Surfaces

Chris G. Van de Walle; J. Neugebauer

doi:10.1103/PhysRevLett.88.066103

First-Principles Surface Phase Diagram for Hydrogen on GaN Surfaces

Chris G. Van de Walle and J. Neugebauer

Phys. Rev. Lett. 88, 066103 – Published 28 January 2002

Abstract

We discuss the derivation and interpretation of a generalized surface phase diagram, based on first-principles density-functional calculations. Applying the approach to hydrogenated GaN surfaces, we find that the Gibbs free energies of relevant reconstructions strongly depend on temperature and pressure. Choosing chemical potentials as variables results in a phase diagram that provides immediate insight into the relative stability of different structures. A comparison with recent experiments illustrates the power of the approach for interpreting and predicting energetic and structural properties of surfaces under realistic growth conditions.

Received 27 August 2001

DOI:https://doi.org/10.1103/PhysRevLett.88.066103

Authors & Affiliations

Chris G. Van de Walle^1,2,3 and J. Neugebauer²

¹Xerox Palo Alto Research Center, 3333 Coyote Hill Road, Palo Alto, California 94304
²Fritz-Haber-Institut der Max-Planck-Gesellschaft, Faradayweg 4-6, D-14195 Berlin-Dahlem, Germany
³Paul-Drude-Institut, Hausvogteiplatz 5-7, D-10117 Berlin, Germany