Quantum size effects on the work function of metallic thin film nanostructures.

ABSTRACT: In this paper, we present the direct observation of quantum size effects (QSE) on the work function in ultrathin Pb films. By using scanning tunneling microscopy and spectroscopy, we show that the very existence of quantum well states (QWS) in these ultrathin films profoundly affects the measured tunneling decay constant kappa, resulting in a very rich phenomenon of "quantum oscillations" in kappa as a function of thickness, L, and bias voltage, V(s). More specifically, we find that the phase of the quantum oscillations in kappa vs. L depends sensitively upon the bias voltage, which often results in a total phase reversal at different biases. On the other hand, at very low sample bias (|V(s)| < 0.03 V) the measurement of kappa vs. L accurately reflects the quantum size effect on the work f

SUBMITTER: Kim J 

PROVIDER: S-EPMC2919909 | biostudies-literature | 2010 Jul

REPOSITORIES: biostudies-literature