Switchable single-molecule electronic and thermoelectric device induced by light in a designed diarylethene molecule

Tremendous efforts have been devoted to studying ordinary and novel properties in molecular-scale. Especially the reversible and controlled electrical and thermoelectric switches, which have been extensively studied experimentally and theoretically. They possess two distinct electronic and thermoelectric transport states actuated by external triggers, such as light, temperature, and electric field. Here, a photochromic diarylethene, linked to a nontriazatriangulene platform covalently, is studied by first-principles calculation. By means of density functional theory, we calculate the density of states and scanning tunneling microscope (STM) images of the designed diarylethene adsorbed on a Au(111) surface. Moreover, the thermoelectric transport properties of diarylethenebased molecular junction with a Au(111) electrode are studied systematically by using nonequilibrium Green's function transport formalism. We illustrate that due to the structure change of the designed diarylethene induced by light, the electronic and thermoelectric transport properties of the junction are completely different. Those differences can be visualized by the calculated electronic transmission eigenchannel and transport pathway. Furthermore, we demonstrate that the structure change of the designed diarylethene can be detected by STM experiments. The present study shows that the designed diarylethene could be a desirable candidate for electronic and thermoelectric molecular switch driven by light.