Fig. 3: Simulated EL diagrams for single-molecule electroluminescence.
From: Anomalously bright single-molecule upconversion electroluminescence
a Energy-level diagram for a single-molecule junction. \({E}_{{{{{{{\rm{T}}}}}}}_{1}}\) (\({E}_{{{{{{{\rm{S}}}}}}}_{1}}\)) is the energy of the lowest excited spin-triplet (spin-singlet) states, \({\phi }_{{{{{{\rm{e}}}}}}}\) (\({\phi }_{{{{{{\rm{h}}}}}}}\)) is the electron (hole) injection barrier defined as the energy difference between the molecular LUMO (HOMO) and the Fermi level of the substrate. The molecular levels are assumed to be pinned to the substrate. b Numerically simulated exciton excitation efficiency \({\eta }_{{{{{{\rm{ex}}}}}}}\) as a function of Vb and \({\phi }_{{{{{{\rm{e}}}}}}}\) based on the quantum master equation model. In each region, only the dominant mechanism is highlighted. The simulation parameters are given in Supplementary Note 5. c Schematics for different one-electron excitation mechanisms.
