Verification of Au Nanodot Size Dependence on Coulomb Step Width by Non-contact Atomic-force Spectroscopy

摘要

We demonstrate single electron counting on an alkanethiol-protected Au nanodot in a double-barrier tunneling structure by noncontact atomic-force spectroscopy (nc-AFS). The Coulomb step width dependence on the Au nanodot diameter is observed. Evaluation of fractional charge Q_0 and contact potential difference by nc-AFS reveals a V_d-independent voltage shift due to Q_0.