Observation of quantum size effects in photoemission from Ag islands on GaAs(110).
A set of extra peaks, which dominate the region of the silver s-p band, are observed in angle-resolved photoemission from Ag islands formed on GaAs(110) by low temperature deposition -and annealing to room temperature. The thickness dependence of peak spacing demonstrates that the new peaks originate from wave vector quantization due to electron confinement. The overall features of the spectra are reproduced within a model based on a superposition of emission from a distribution of island sizes, and are interpreted as quantum size erects in these small metal «quantum dots»