Fig. 1: Resonant tunneling through a molecule adsorbed on a thin NaCl film.
From: Charge-state lifetimes of single molecules on few monolayers of NaCl
a Schematic depiction of the transient negative charging of the molecule at positive bias. Chemical structures of the utilized molecules (H2Pc and ZnPc) are shown in b. The charging time through the vacuum barrier τc can be varied by changing the distance between tip and molecule; thicker arrows indicate smaller charging times. The discharging time, i.e., the charge-state lifetime, through the NaCl film τd is governed by the film thickness. The two cases that are schematically depicted here correspond to tip-molecule distances where τc is longer (long, thin arrow) and shorter (short, thick arrow) compared to τd. c Corresponding one-electron picture of the double-barrier tunnel junction shown in a.
