A self-formed nanonetwork meshed Pt layer formed on the epitaxial (0 0 0 1) GaN substrate upon thermal annealing. Electron backscatter diffraction analysis shows that, while the meshed Pt layer was forming on the GaN surface, Pt atoms rearranged themselves in a (1 1 1)-preferred orientation on (0 0 0 1) GaN. The (1 1 1) Pt/(0 0 0 1) GaN interface represents the most energy-favored stacking configuration. This unique meshed Pt layer demonstrates a relatively high transmittance in visible range, which can be used as a high-reflectivity/low-resistance p-GaN contact for high-power LEDs. (C) 2010 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.