Conductance characteristics of naphthopyran as a light-sensitive molecular optical junction: a joint NEGF-DFT and TD-DFT study

Here, the electronic conductance characteristics of naphthopyran were studied using non-equilibrium Green’s function density functional theory (NEGF-DFT) and time-dependent density functional theory (TD-DFT) methods. When naphthopyran is exposed to UV or visible light, the specified structure can switch between its open and closed forms. Molecular geometries, surface material types (platinum, gold, and silver), switching ratios, gaps between HOMO and LUMO levels, transmission spectra, and PDOS at different bias voltages were studied. It was found that the conductance of naphthopyran changed from an off-state (high resistance) to an on-state (low resistance) when the molecular optical junction converted from the open to the closed configuration.