"V"-Shaped Changing Electronic Performance of Iodinene-Based Nanoflakes as a Function of Width

Special structures and prominent performance make 2D iodinene more appealing and valuable at the molecular level. Here, new-type electronic devices have been constructed with iodinene-based nanoflakes in different sizes and are theoretically studied for electronic transport properties. Our findings reveal that iodinene-based nanoflakes possess great electron transport suppression, achieving the same function as SiO₂ on single molecule scale. Such transport suppression shows surprisingly nonlinear "V"-shaped trend with the width of the iodinene-based nanoflake. The medium-width iodinene-based nanoflake exhibits the strongest electron transport suppression, while the narrowest and widest ones display the largest electron transmission coefficients due to delocalized transmission eigenstates. Essentially, the weakest electron transport originates from an extremely small DOS and wide HOMO-LUMO gap. Specifically, increasing the width would diminish the extension of electronic states for the dominant transport orbitals, resulting in more butterfly-like electronic states. In non-equilibrium, negative differential resistance effect can be observed in iodinene-based devices, caused by the weakening and staying away from the Fermi level of transmission peaks influenced by the bias. Our findings provide insights into the relationship between the width of iodinene-based nanoflake and electronic transport properties, and lay a foundation in the device design and applications in molecular insulators and controllable-functional devices.