Computational Study of Interfaces Between 2D SnTe and Oligomers of Aliphatic Polymers

Density functional theory has been used to study the interactions between oligomers of aliphatic polymers and the two-dimensional (2D) material SnTe. Polyethylene, polyethylene glycol, polyvinyl chloride, poly(vinyl alcohol), and polyvinylidene fluoride were found to physisorb on the SnTe nanosheet, with poly(vinyl alcohol) having the strongest interactions. Polyvinylidene fluoride and polyvinyl chloride also interacted relatively strongly with SnTe. Due to the structural and electronic anisotropy of SnTe, eight different oligomer adsorption positions were tested. Two different rotations, each with different numbers of heteroatoms adjacent to the SnTe nanosheet, were also tested for polyvinyl chloride, poly(vinyl alcohol) and polyvinylidene fluoride. The orientation relative to the nanosheet had minimal effect on the SnTe–oligomer interactions. However, the number of heteroatoms adsorbed close to the nanosheet had significant effects on the interactions, depending on the oligomer in question. The structural properties, charge transfer and band structures of the SnTe–oligomer complexes were investigated to determine whether oligomer adsorption can tune the properties of SnTe. Although some structural distortion was observed, the electronic properties of the complexes remained nearly unchanged from isolated SnTe. Due to the large number of factors affecting extended molecule adsorption, there were no systematic correlations observed in the results, and general predictions of SnTe–oligomer behavior could not be made. The results provide evidence that aliphatic polymers can serve as support for SnTe with minimal influence on the properties of the material.