STM observation of a single diarylethene flickering

Abstract

We report the STM observation of single diarylethene derivatives (DD) embedded into alkylthiol self-assembled monolayers (SAM) on Au(111). Telegraph noise in the data shows that the molecular conductance oscillates between two states. Comparing our results to the ones obtained by other teams observing conductance flickering with systems in the same geometry, we relate the two observed states to the two isomeric configurations of the molecule under study.

Photochromic Diarylethenes Designed for Surface Deposition: From Self‐Assembled Monolayers to Single Molecules

“…(Figure f) They measured these uncontrolled reversible changes over time and proposed three possible sources of these fluctuations: conformational changes by the molecule, changes in the geometry of Au−S bond, or diffusion of species from the environment which can change the electronic properties of the compound. They did not include isomerization between o and c forms, but proposed hot tunneling electrons with energy of a “few hundreds of meV” as the cause of these fluctuations …”

Molecular adlayer and photo-induced structural transformation of a diarylethene derivative on Au(111) investigated with scanning tunneling microscopy

“…To fabricate a device based on photoactive molecules, it is significant to know molecular isomerization/ reaction and structural transformation occurred at surfaces under photo-irradiation [16][17][18]. Along with many techniques such as X-ray diffraction and surface-enhanced Raman spectroscopy available to examine photoreaction at surfaces [19,20], scanning tunneling microscopy (STM) has been proved to be a powerful tool to study the photoresponsive systems owning to its ability to provide direct real space evidence at molecular level [21][22][23][24][25][26][27][28][29][30][31]. By using STM, the photochemical process and structural transformation of photoactive molecules can be scrutinized before and after photoirradiation with submolecular resolution.…”

“…For example, Katsonis et al studied the reversible conductance switching of diarylethenes bonded on a gold surface through a Au-S linker [40]. Compared to the well-documented azobenzene system, there are few reports on the self-assembly and photoisomerization of diarylethene derivatives on a solid substrate [30,31], which is important to build up molecular optoelectronic devices based on diarylethene.…”

Photoswitching of electron transfer property of diarylethene–viologen linked molecular layer constructed on a hydrogen-terminated Si(111) Surface

“…[8][9][10] Although surface immobilization of diarylethene moiety is essential for useful application, only few groups have reported the introduction of diarylethene derivatives into surface molecular layers via covalent bond because of difficulty in synthesis of molecule with surface attachment, linker and diarylethene moieties. [11][12][13][14][15][16][17][18][19][20][21] Recently, we reported a construction of mono-and multi-viologen layers on Si(111) surface, by sequential surface reactions, i.e., layer-by-layer growth, without loosing their electron mediation capability. [22,23] at 80 °C for 20 min.…”