The Gundlach oscillation in scanning tunneling spectroscopy is used to measure the work function of Pb quantum islands grown on a Cu(111) substrate. The results reveal that the work function varies in oscillation with island thickness, which can be attributed to the existence of the quantum well states within the islands. The undulation of the work function is consistent with the theoretical calculations for a thickness from 6 to 15 atomic layers. While the island is grown layer-by-layer, it is found that the work function decreases (increases) whenever one (two) subband(s) is(are) added to the occupied states of the island.
|頁（從 - 到）||855-862|
|期刊||Chinese Journal of Physics|
|出版狀態||Published - 1 12月 2010|