Ambipolar transition voltage spectroscopy: Analytical results and experimental agreement

This work emphasizes that the transition voltages Vₓ for both bias polarities (V 0) should be used to properly determine the energy offset ₀ of the molecular orbital closest to electrodes' Fermi level and the bias asymmetry in molecular junctions. Accurate analytical formulas are deduced to estimate ₀ and solely in terms of Vₓ. These estimates are validated against experiments, by showing that full experimental I-V curves measured by Beebe et al. Phys. Rev. Lett. 97, 026801 (2006) and Tan et al. Appl. Phsy. Lett. 96, 013110 (2010) for both bias polarities can be excellently reproduced.