Figure 1

The (a) untreated and (b) after AHC $\mathrm{In}4d$ semicore level spectra of the InN sample, GS1409, (dots), with the corresponding curve-fits (thick lines). The background and peak components (thin lines) of the fits are also shown. Three components were required to fit the as-loaded $\mathrm{In}4d$ level, corresponding to In-O, In-N, and In-In bonds. After AHC, the In-O bond is absent and the In-N bond has an increased signal. A feature at $\sim 15\mathrm{eV}$ in both spectra is from the $\mathrm{N}2s$ orbital. The insets show the magnified valence band region for both the as-loaded and after AHC spectra. The valence-band maximum, after AHC, was extrapolated from the leading edge of the valence peak $P_I$. Also shown for comparison is the valence-band spectrum of GS1469 after AHC (gray triangles) using the same intensity scale. The extra peak (highlighted by the gray arrow) close to zero binding energy in the valence-band spectrum of GS1469 indicates metallic In droplet formation.Reuse & Permissions

Figure 2

The SEM images of (a) GS1409 and (b) GS1469 after AHC cycles for the same $1\mu \mathrm{m}$ scale. For GS1409, a flat and featureless surface is observed in contrast to the large In droplets on the surface of GS1469.Reuse & Permissions

Figure 3

The (a) XPS valence-band spectrum, with the Shirley background subtracted, is plotted (dots), and the (b) DFT-LDA calculated valence-band structure using the revised $pd$ repulsion. The resultant calculated VB-DOS is shown in (a) without (thin line) and with (thick line) $0.45\mathrm{eV}$ broadening (scaled to match the intensity of the x-ray photoemission spectrum). The broadened VB-DOS is horizontally offset by $1.4\mathrm{eV}$ for comparison with the XPS spectrum.Reuse & Permissions