Electronic structure of gold nanoparticles deposited on SiOx/Si(100)

Nanosize gold particles were prepared by Ar+ ion sputtering of island-like 10-nm-thick film deposited onto Si/SiOx substrate. The valence band of the gold particles was measured by means of photoelectron spectroscopy and infrared (IR) absorbance. The size of the particles was determined by transmission electron microscopy (TEM). The valence band of Au nanoparticles is strongly redistributed with decreasing size, involving mostly the lowest and the highest binding energy part of the Au 5d valence states. This effect can be attributed more to the redistribution than to the narrowing of the 5d states.