Single molecule piezoelectrics and ferroelectrics: From theory to experiment

摘要: This dissertation proposes and studies the idea of single molecule piezoelectrics ferroelectrics via both computational experimental means. The research is aimed to open a new area piezoelectric/ferroelectric materials for next generation nanoscale, flexible, efficient, multifunctional electronic devices. Density functional theory (DFT) calculations are employed study electric field induced conformational change (piezoelectric effect) three molecular springs: asymmetrically substituted helicenes, phenanthrenes, oligoaminoacids driven polarization inversion (ferroelectric bowls (buckybowls). Molecular structure, groups, dipole moment, regiochemistry discussed as factors generate good ferroelectrics. A significantly large piezoelectric coefficient (up 272 pm/V hypothetical helicene derivative 450 buckybowl derivative) broad range (0.26 V/nm - 9.05 buckybowls) predicted. Our proposed could potentially compete with conventional piezo/ferroelectric (e.g. zinc oxide (ZnO), polyvinylidene difluoride (PVDF), lead zirconium titanate (PZT), etc.). The effect molecules experimentally demonstrated sample patterned self-assembled monolayers (SAMs) techniques piezoresponse force microscopy (PFM) Fourier-transform infrared spectroscopy (FTIR). Combined our predictions, we believe that class may be created from “bottom up” based on changes, which material resources fabricating scale, ultrathin, lightweight