# Switching mechanism of photochromic diarylethene derivatives molecular junctions

## TL;DR

This study investigates the electronic transport and switching mechanisms of photochromic diarylethene molecular junctions using advanced computational methods, revealing significant on-off current ratios and robust switching behavior across various modifications.

## Contribution

It provides a detailed theoretical analysis of the switching mechanism in diarylethene derivatives, demonstrating high on-off ratios and robustness to chemical substitutions and anchoring variations.

## Key findings

- On-off current ratio of about two orders of magnitude.
- Distinct transmission spectra for open and closed configurations.
- Switching behavior is robust to chemical substitutions and anchoring changes.

## Abstract

The electronic transport properties and switching mechanism of single photochromic diarylethene derivatives sandwiched between two gold surfaces with closed and open configurations are investigated by a fully self-consistent nonequilibrium Green's function method combined with density functional theory. The calculated transmission spectra of two configurations are strikingly distinctive. The open form lacks any significant transmission peak within a wide energy window, while the closed structure has two significant transmission peaks on the both sides of the Fermi level. The electronic transport properties of the molecular junction with closed structure under a small bias voltage are mainly determined by the tail of the transmission peak contributed unusually by the perturbed lowest perturbed unoccupied molecular orbital. The calculated on-off ratio of currents between the closed and open configurations is about two orders of magnitude, which reproduces the essential features of the experimental measured results. Moreover, we find that the switching behavior within a wide bias voltage window is extremely robust to both substituting F or S for H or O and varying end anchoring atoms from S to Se and Te.