Could conjugated polymers be the key to unlocking a new era of organic piezoelectrics? This work, shows that state-of-the-art organic piezoelectrics are outperformed by piezoelectric conjugated polymers, mostly thanks to strongly anomalous effective charges of carbon, larger than 5e—ordinary values being of the order of 1e—and reaching the giant value of 30e for band gaps of the order of 1 eV. The study is focused on density functional theory and conjugated polymers. First-principles density functional theory (DFT) calculations performed in two representative conjugated polymers using hybrid functionals, show that state-of-the-art organic piezoelectric are outperformed by piezoelectric conjugated polymers. The results show mostly thanks to strongly anomalous effective charges of carbon, larger than 5e—ordinary values being of the order of 1e. A structural (ferroelectric) phase transition further contributes to an enhancement of the piezoelectric response reminiscent of that observed in piezoelectric perovskites close to morphotropic phase boundaries.
Published in npj Computational Materials, this research aligns with the journal's focus on using computational methods to advance materials science. It explores the properties of conjugated polymers for piezoelectric applications, contributing to the development of novel materials with enhanced functionalities. The study lies at the intersection of computational chemistry, physics, and materials science.