2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/26116We have observed tunable negative differential resistance (NDR) in scanning tunneling spectroscopy measurements of a double layer of C60 molecules on a metallic surface. Using a simple model we show that the observed NDR behavior is explained by voltage-dependent changes in the tunneling barrier height.Mesoscale and Nanoscale PhysicsMaterials Sciencetext