We developed a metrology approach for single molecular device for performance analysis of molecular nanoelectronics devices to probe the energy gap in single molecular devices. Molecular Nanoelectronics technologies at early time were very immature both on technological and scientific levels. The closeness of energy of the high occupied molecular orbital - low unoccupied molecular orbital (HOMO-LUMO) energy gap was detected by electric (ΦB∑) and optic measurements (Δ∘),ΦB∑≈Δ∘.The ‘electrical gap’, ΦB∑,consists of sum of two barriers, ΦBLUMO and ΦBHOMO, for tunneling of electrons and holes through molecular barrier correspondingly, in devices with a different pair of electrodes at low biases and difference in work function, ΔWF, between these metal electrodes: ΦB∑ = ΦBLUMO + ΦBHOMO+ ΔWF. We created and examined two devices using a pair of of gold (Au) and aluminum (Al) electrodes to find ΦBHOMO, (ΦBAu)and ΦBLUMO (ΦBAl) using Simmons tunneling model. The symbols ΦBLUMO and ΦBHOMO signify difference in energy between HOMO and LUMO levels in a molecular system with respect to the Au and Al electrode’s Fermi level. In nanoscale devices, Comparison of ΦB∑ and Δ∘ can reveal the presence of electrically active molecules between electrodes.
Author(s) Details:
Vladimir Burtman,
Department
of Physics and Astronomy, University of Utah, James Fletcher Building, 115 1400
E, Salt Lake City, UT 84112-0111, USA.
Please see the link here: https://stm.bookpi.org/NFPSR-V4/article/view/8753
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