Photoferroelectricity in di-phenylalanine peptide nanotubes

Molecular modeling and computational analysis are carried out for photo-induced and photo-luminescence effects in di-phenylalanine (FF) peptide nanotubes (PNT) using quantum-chemical semi-empirical approach PM3 in unrestricted Hartree-Fock (UHF) and restricted (RHF) approximation. HyperChem package tool is applied. The data obtained from the main photo-ferroelectric phenomena (the values of the forbidden band gap Eg and its shift under an applied electrical field, “red” shift of the photo-luminescence after photo-excitation) are compared with phenomenological thermodynamic theory of photo-ferroelectricity based on the Landau-Ginzburg-Devonshire expansion. The data computed are in good agreement with those obtained within phenomenological thermodynamic description. It means that the proposed quantum description and computational analysis throw new light on our understanding of these important phenomena and could serve as a new theoretical and modeling basis for investigation of photoferroelectricity in such peptide tubular molecular nanostructures and other related systems.