A Multidimensional Approach to Structural Transformation Through Functionalization of Tellurene

Two dimensional (2D) Tellurene (Te) structures have recently been synthesized, and have been shown to possess high mobility and stability. Using density functional theory (DFT) and molecular dynamics (MD), we investigated the stability and electronic structure of 2D, and phase sheets, and their hydrogen, oxygen, and fluorine functionalized counterparts. Our calculations show that bare - and -Te sheets are stable and have band gaps of 0.44 eV and 1.02 eV respectively. We see that H, O and F destabilize -Te; F and H cause -Te layers to separate into functionalized atomic chains; and O causes -Te to totally transform into a Te₃O₂-like structure. Also, we studied the coverage effects of different concentrations of H and O on and β-Te and found that the full coverage case results in the highest binding energy and stability for both adatoms. Finally, we examined the stability and binding nature of functionalized β-Te on a GaSe substrate. We noted that having O and H impurities not only enhances the stability of Te layer, but also results in a strong binding energy on GaSe substrate. Our results indicate that Tellurene monolayers and functionalized counterparts are suitable for future optoelectronic devices and as metallic contacts in nanoscale junctions.