Surface and electronic structure of Ga0.92In0.08N thin film investigated by photoelectron spectroscopy

The surface and electronic structure of (Ga0.92InN)-N-0.08 layers grown by metal organic chemical vapor deposition (MOCVD) have been investigated by means of photoemission. Stability of chemical composition of the surface subjected to At+ ion sputtering was proven by means of X-ray photoemission spectroscopy. The analysis of the relative intensities of In 3d, Ga 3p, and N Is peaks showed that argon ion bombardment does not change significantly the relative contents of the layer constituents. Simultaneous efficient removal of the main contaminants (O and C) was observed during the sputtering procedure, proving that argon sputtering can be used as a method for preparation of clean Ga1-xInxN surfaces. For a clean (0001)-(1 x 1) surface prepared by repeated cycles of Ar+ ion sputtering and annealing, electronic structure was investigated. The band structure was explored along the Gamma-A direction of the Brillouin zone, measuring angle-resolved photoemission spectra along the surface normal. A similar set of data was also acquired for the same surface of GaN layer. Comparison of the collected data revealed an additional feature at the valence band edge, which can be ascribed to the presence of In in the layer. (c) 2004 Elsevier B.V. All rights reserved.